Glyphosate formulations containing amidoalkylamine surfactants

ABSTRACT

An herbicidal composition comprising (a) glyphosate or a derivative thereof, (b) an amidoalkylamine surfactants having the general structure: 
     
       
         
         
             
             
         
       
     
     wherein R 1  is a hydrocarbyl having from about 1 carbon atoms to about 22 carbon atoms, and R 2 , R 3 , and R 4  are each independently hydrocarbyl having from about 1 carbon atom to about 6 carbon atoms; and (c) at least one co-surfactant.

This application is a continuation of U.S. application Ser. No.15/657,461, filed Jul. 24, 2017, now U.S. Pat. No. 10,925,284, which isa continuation of U.S. application Ser. No. 12/568,167, filed Sep. 28,2009 and claims the benefit of U.S. provisional Application No.61/100,961, filed Sep. 29, 2008, the entire contents of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to herbicidal compositionscomprising glyphosate and more specifically, to herbicidal compositionscomprising glyphosate and surfactant blends particularly tailored toincrease the stability of and reduce the toxicity of the herbicidalcompositions.

BACKGROUND OF THE INVENTION

N-phosphonomethylglycine (“glyphosate”) is an effective post-emergentfoliar-applied herbicide. In its acid form, the structure of glyphosateis:

Since glyphosate in its acid form is relatively insoluble in water(1.16% by weight at 25° C.), it is typically formulated as awater-soluble salt.

Glyphosate is typically formulated as a monobasic, dibasic, or tribasicsalt. Various salts of glyphosate, methods for preparing salts ofglyphosate, formulations of glyphosate or its salts and methods of useof glyphosate or its salts for killing and controlling weeds and otherplants are disclosed in U.S. Pat. No. 4,507,250 to Bakel, U.S. Pat. No.4,481,026 to Prisbylla, U.S. Pat. No. 4,405,531 to Franz, U.S. Pat. No.4,315,765 to Large, U.S. Pat. No. 4,140,513 to Prill, U.S. Pat. No.3,977,860 to Franz, U.S. Pat. No. 3,853,530 to Franz, and U.S. Pat. No.3,799,758 to Franz. The aforementioned patents are incorporated hereinin their entirety by reference.

Typical glyphosate salts include, for example, themono(isopropylammonium) (“IPA”), potassium, sodium, monoethanolammonium(“MEA”), trimethylsulfonium (“TMS”), ammonium, diammonium salts,n-propylamine, ethylamine, ethylenediamine, and hexamethylenediaminesalts. The most widely used salt of glyphosate is the IPA salt.Commercial herbicides of Monsanto Company having the IPA salt ofglyphosate as active ingredient include Roundup®, Roundup® Ultra,Roundup® Xtra, and Rodeo® herbicides. These are aqueous solutionconcentrate formulations and are generally diluted in water by the userprior to application to plant foliage. Commercially formulated TMS saltis used, for example, in Touchdown® herbicide of Zeneca (Syngenta).

Glyphosate salts are typically co-formulated with a surfactant tomaximize herbicidal efficacy. However, the development of concentratedglyphosate formulations in the range of 480 g a.e./L to 540 g a.e./L ischallenging due to the limited compatibility of surfactants at highglyphosate loadings. In this context and throughout this specification“g a.e./L” means grams acid equivalent per liter of solution, whichrefers to the concentration of glyphosate in its acid form. It isparticularly challenging to formulate high load concentrates employingthe potassium glyphosate salt or the diammonium glyphosate salt.

Current commercial diammonium glyphosate formulations typically containfrom 360 g a.e./L to 369 g a.e./L glyphosate and employ relativelycostly quaternary ammonium surfactants. The surfactant loadings are keptlow in these formulations in order to maintain good eye toxicity profileand to be cost competitive. Problematically, low glyphosate loadingcoupled with low surfactant concentrations yields formulationscharacterized by reduced bioefficacy as compared to commercialformulations known in the art.

SUMMARY OF THE INVENTION

Among the various aspects of the present invention may be noted theprovision of bio-efficacious herbicidal compositions having highglyphosate and surfactant loads. The herbicidal compositions of theinvention are stable when formulated as herbicidal concentrates and whentank-mixed with co-herbicides. The present invention further providesherbicidal compositions characterized by reduced toxicity and reducedeye irritation. The herbicidal compositions of the invention are furthercompatible with a variety of glyphosate salts, for example, thepotassium salt, the diammonium salt, the monoethanolamine salt, orcombinations thereof.

Briefly, therefore, the present invention is directed to a liquidcomposition comprising glyphosate or a derivative thereof, wherein theglyphosate concentration is greater than 360 grams acid equivalent perliter. The composition further comprises an amidoalkylamine surfactantof structure (I):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from 1 toabout 22 carbon atoms, R₂ and R₃, are each independently hydrocarbyl orsubstituted hydrocarbyl having from 1 to about 6 carbon atoms, and R₄ ishydrocarbylene having from 1 to about 6 carbon atoms. The compositionfurther comprises at least one co-surfactant comprising an alkoxylatedtertiary amine, an alkoxylated quaternary amine, an alkoxylated tertiaryetheramine, an alkoxylated quaternary etheramine, an alkoxylatedetheramine oxide, an alkoxylated tertiary amine oxide, an alkoxylatedalcohol, a phosphate ester of alkoxylated tertiary amine, a phosphateester of alkoxylated etheramine, a phosphate ester of alkoxylatedalcohol, or a combination thereof. The alkoxylated tertiary aminesurfactant is of structure (II):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4to about 22 carbon atoms, R₂ and R₃ are each independentlyhydrocarbylene having 2, 3, or 4 carbon atoms, and the sum of x and y isan average value ranging from about 2 to about 50. The alkoxylatedquaternary amine surfactant is of structure (III):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from 4 toabout 22 carbon atoms, R₂ and R₃ are each independently hydrocarbylenehaving 2, 3, or 4 carbon atoms, R₄ is hydrocarbyl or substitutedhydrocarbyl having from 1 to about 4 carbon atoms, the sum of x and y isan average value ranging from about 2 to about 50, and X is a chargebalancing counter-anion. The alkoxylated tertiary etheramine surfactantis of structure (IV):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4to about 22 carbon atoms; R₂, R₃ and R₄ are each independentlyhydrocarbylene having 2, 3, or 4 carbon atoms; m is an average numberfrom about 1 to about 10; and the sum of x and y is an average valueranging from about 2 to about 60. The alkoxylated quaternary etheraminesurfactant is of structure (V):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4to about 22 carbon atoms; R₂, R₃ and R₄ are each independently ahydrocarbylene having 2, 3, or 4 carbon atoms; m is an average numberfrom about 1 to about 10; the sum of x and y is an average value rangingfrom about 2 to about 60; R₅ is hydrocarbyl or substituted hydrocarbylhaving from 1 to about 4 carbon atoms; and A is a charge balancingcounter-anion. The alkoxylated etheramine oxide surfactant is ofstructure (VI):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4to about 22 carbon atoms; R₂, R₃ and R₄ are each independentlyhydrocarbylene having 2, 3, or 4 carbon atoms; m is an average numberfrom about 1 to about 10; and the sum of x and y is an average valueranging from about 2 to about 60.

The alkoxylated tertiary amine oxide surfactant is of structure (VII):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4to about 22 carbon atoms; R₂ and R₃ are each independentlyhydrocarbylene having 2, 3, or 4 carbon atoms; and the sum of x and y isan average value ranging from about 2 to about 50. The alkoxylatedalcohol surfactant is of structure (VIII):

R₁—O—(R₂O)_(n)H  Structure (VIII)

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4to about 22 carbon atoms; R₂ is hydrocarbylene having 2, 3, or 4 carbonatoms; n is an average value ranging from about 2 to about 50. Thephosphate ester of the alkoxylated tertiary amine surfactant is ofstructure (IXa) or structure (IXb):

wherein each R₁ is independently hydrocarbyl or substituted hydrocarbylhaving from about 4 to about 22 carbon atoms, R₂ and R₃ are eachindependently hydrocarbylene having 2, 3, or 4 carbon atoms, the sum ofeach x and y group is independently an average value ranging from about2 to about 60, and R₄ and R₅ are each independently hydrogen,hydrocarbyl or substituted hydrocarbyl having from 1 to about 6 carbonatoms. The phosphate ester of alkoxylated etheramine surfactant is ofstructure (Xa) or structure (Xb):

wherein each R₁ is independently hydrocarbyl or substituted hydrocarbylhaving from about 4 to about 22 carbon atoms; each R₂, R₃ and R₄ areeach independently hydrocarbylene having 2, 3, or 4 carbon atoms; each mis independently an average number from about 1 to about 10; the sum ofeach x and y group is independently an average value ranging from about2 to about 60; and R₅ and R₆ are each independently hydrogen,hydrocarbyl or substituted hydrocarbyl having from 1 to about 6 carbonatoms. And the phosphate ester of alkoxylated alcohol surfactant is ofstructure (XIa) or (XIb):

wherein each R₁ is independently hydrocarbyl or substituted hydrocarbylhaving from about 4 to about 22 carbon atoms; each R₂ is independentlyhydrocarbylene having 2, 3, or 4 carbon atoms; each m is independentlyan average number from about 1 to about 60; and R₃ and R₄ are eachindependently hydrogen, a hydrocarbyl or substituted hydrocarbyl havingfrom 1 to about 6 carbon atoms.

In another aspect, the present invention is directed to a liquidcomposition comprising glyphosate or a derivative thereof. Thecomposition further comprises an amidoalkylamine surfactant of structure(I) as described above. The composition further comprises at least oneco-surfactant comprising an alkoxylated tertiary etheramine of structure(IV), an alkoxylated quaternary etheramine of structure (V), analkoxylated etheramine oxide of structure (VI), an alkoxylated tertiaryamine oxide of structure (VII), a phosphate ester of alkoxylatedtertiary amine of structure (IXa) or (IXb), a phosphate ester ofalkoxylated etheramine of structure (Xa) or (Xb), a phosphate ester ofalkoxylated alcohol of structure (XIa) or (XIb), each of which asdescribed above, or a combination thereof.

In another aspect, the present invention is directed to a solidcomposition comprising glyphosate or a derivative thereof. Thecomposition further comprises an amidoalkylamine surfactant of structure(I) as described above. The composition further comprises at least oneco-surfactant comprising an alkoxylated tertiary amine of structure(II), an alkoxylated quaternary amine of structure (III), an alkoxylatedtertiary etheramine of structure (IV), an alkoxylated quaternaryetheramine of structure (V), an alkoxylated etheramine oxide ofstructure (VI), an alkoxylated tertiary amine oxide of structure (VII),an alkoxylated alcohol of structure (VIII), a phosphate ester ofalkoxylated tertiary amine of structure (IXa) or (IXb), a phosphateester of alkoxylated etheramine of structure (Xa) or (Xb), a phosphateester of alkoxylated alcohol of structure (XIa) or (XIb), each of whichas described above, or a combination thereof. The weight ratio ofglyphosate grams acid equivalent to total surfactant in grams is fromabout 3:1 to about 5:1.

In yet another aspect, the present invention is directed to a solidcomposition comprising glyphosate or a derivative thereof. Thecomposition further comprises an amidoalkylamine surfactant of structure(I) as described above. The composition further comprises at least oneco-surfactant comprising an alkoxylated tertiary amine of structure(II), an alkoxylated quaternary amine of structure (III), an alkoxylatedtertiary etheramine of structure (IV), an alkoxylated quaternaryetheramine of structure (V), an alkoxylated etheramine oxide ofstructure (VI), an alkoxylated tertiary amine oxide of structure (VII),a phosphate ester of alkoxylated tertiary amine of structure (IXa) or(IXb), a phosphate ester of alkoxylated etheramine of structure (Xa) or(Xb), a phosphate ester of alkoxylated alcohol of structure (XIa) or(XIb), each of which as described above, or a combination thereof.

Other objects and features will be in part apparent and in part pointedout hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is graph depicting the viscosity of diammonium glyphosateformulations as a function of surfactant type and surfactant loading.The data were obtained according to the method described in Example 1.

FIG. 2 is a graph of bioefficacy data from a greenhouse study. The testformulations included Adsee C80W surfactant. The data were obtainedaccording to the method described in Example 2.

FIG. 3 is a graph of bioefficacy data from a greenhouse study. The testformulations included a C₈-C₁₀ amidopropyl dimethylamine surfactant. Thedata were obtained according to the method described in Example 3.

FIG. 4 is a graph of bioefficacy data from a greenhouse study. The testformulations included a C₈-C₁₀ amidopropyl dimethylamine surfactant at aglyphosate to surfactant ratio of 4:1. The data were obtained accordingto the method described in Example 4.

DESCRIPTION OF THE EMBODIMENT(S) OF THE INVENTION

In general, the present invention is directed to an herbicidalcomposition comprising glyphosate or a salt or ester thereof, anamidoalkylamine surfactant, and at least one co-surfactant that is not,by itself, typically compatible in a high load glyphosate composition.That co-surfactant may be selected from among an alkoxylated tertiaryamine, an alkoxylated quaternary amine, an alkoxylated etheramine, analkoxylated quaternary etheramine, alkoxylated etheramine oxide, analkoxylated tertiary amine oxide, an alkoxylated alcohol, a phosphateester of alkoxylated tertiary amine, a phosphate ester of alkoxylatedetheramine, and a phosphate ester of alkoxylated alcohol. In someembodiments, for example, the herbicidal composition comprisesglyphosate or a salt or ester thereof, an amidoalkylamine surfactant,and at least one co-surfactant selected from among an alkoxylatedtertiary amine, an alkoxylated quaternary amine, or a combinationthereof. In some embodiments, the herbicidal composition comprisesglyphosate or a salt or ester thereof, an amidoalkylamine surfactant,and at least one co-surfactant selected from among an alkoxylatedetheramine, an alkoxylated quaternary etheramine, or a combinationthereof. In some embodiments, the herbicidal composition comprisesglyphosate or a salt or ester thereof, an amidoalkylamine surfactant,and at least one co-surfactant selected from among an alkoxylatedetheramine oxide, an alkoxylated tertiary amine oxide, or a combinationthereof. In some embodiments, the herbicidal composition comprisesglyphosate or a salt or ester thereof, an amidoalkylamine surfactant,and an alkoxylated alcohol. In some embodiments, the herbicidalcomposition comprises glyphosate or a salt or ester thereof, anamidoalkylamine surfactant, and at least one co-surfactant selected fromamong a phosphate ester of alkoxylated tertiary amine, a phosphate esterof alkoxylated etheramine, and a phosphate ester of alkoxylated alcoholor a combination thereof. The composition may be an aqueous or solidherbicidal concentrate having a high load of glyphosate component or aready to use formulation (“RTU”) prepared by the dilution of herbicidalconcentrates with water.

The high load glyphosate concentrates of the present invention arepossible through the use of amidoalkylamine surfactants which have beendiscovered to be compatible with a wide variety of glyphosate salts.Advantageously, the surfactants have been discovered to be compatiblewith the diammonium salt, the potassium salt, and the monoethanolaminesalt of glyphosate and enable the preparation of stable concentrateseven at high concentrations of those glyphosate salts.

It has been further discovered that amidoalkylamine surfactants areefficient coupling agents to a variety of co-surfactants, for example,alkoxylated tertiary amine co-surfactants and/or alkoxylated quaternaryamine co-surfactants, thereby allowing glyphosate salt loadings of 480 ga.e./L to 600 g a.e./L, coupled with high surfactant loadings of 120 ga.e./L to 150 g a.e./L, for example, a glyphosate salt loading of about540 g a.e./L coupled with a surfactant loading of about 135 g a.e./L.High surfactant loadings of alkoxylated tertiary amine co-surfactantsand/or alkoxylated quaternary amine co-surfactants combined withamidoalkylamine surfactants as coupling agents improves the formulationbioefficacy. Thus, formulations containing blends of amidoalkylaminesurfactant coupling agents with at least one co-surfactant selected fromamong an alkoxylated tertiary amine, an alkoxylated quaternary amine, analkoxylated etheramine, an alkoxylated quaternary etheramine,alkoxylated etheramine oxide, an alkoxylated tertiary amine oxide, analkoxylated alcohol, a phosphate ester of alkoxylated tertiary amine, aphosphate ester of alkoxylated etheramine, and a phosphate ester ofalkoxylated alcohol offer formulation stability as well as comparable,and in some cases, improved bioefficacy over current commercialstandards.

It has further been discovered that employing a surfactant blendcomprising amidoalkylamine surfactant coupled with at least one otherco-surfactant improves the long term storage stability of high loadglyphosate formulations. In this regard, high load glyphosateformulations comprising the surfactant blend of the present inventioncomprise a single phase (i.e., lack precipitates, flocculation, etc.) attemperatures ranging from about −20° C. to about 60° C. for durations ofat least four weeks. The use of amidoalkylamine surfactants enables thepreparation of high load glyphosate formulations comprising a higherproportion (relative to the total surfactant concentration) ofco-surfactant, which further improves the long term stability of theherbicidal compositions of the present invention.

Moreover, the use of a surfactant blend comprising amidoalkylaminesurfactant coupled with at least one other co-surfactant improves thecompatibility of glyphosate compositions with co-herbicides,particularly when such co-herbicides are tank-mixed with dilute, readyto use formulations just prior to use.

It has yet been further discovered that the glyphosate formulations ofthe present invention comprising surfactant blends are characterized bydecreased eye irritation, skin toxicity, and eco-toxicity as compared tosurfactants in known glyphosate formulations. Therefore, amidoalkylaminesurfactants can replace conventional surfactants, such as ethoxylatedcocoamines, without adversely affecting glyphosate bioefficacy, and insome cases improving bioefficacy.

The glyphosate component of the compositions of the present invention istypically primarily responsible for plant suppression or death (i.e.,bioefficacy) and is instrumental in imparting long-term herbicidalcontrol. The glyphosate component comprises glyphosate acid and/or aderivative thereof. Derivatives include salts, esters, or compoundswhich are converted to glyphosate in plant tissues or which otherwiseprovide glyphosate anions. In this regard it is to be noted that theterm “glyphosate,” “glyphosate derivative,” and “glyphosate component”when used herein is understood to encompass glyphosate, derivatives andmixtures thereof unless the context requires otherwise. Furthermore, theterm “agronomically acceptable” includes glyphosate derivatives thatallow agriculturally and economically useful herbicidal activity of aglyphosate anion in residential or industrial applications.

In the aqueous herbicidal compositions of the present invention, it ispreferred that the glyphosate component predominantly comprise one ormore of the more water-soluble salts of glyphosate. As used throughoutthis specification, the expression “predominantly comprises” means morethan 50%, preferably at least about 75%, and more preferably at leastabout 90% by weight of the component of the herbicidal composition ismade up of the specified compound(s). A glyphosate componentpredominantly comprising one or more of the various salts of glyphosateis preferred in part because their increased water solubility allowsformulation of highly concentrated herbicidal compositions that can beeasily transported and readily diluted with water in the preparation ofsprayable RTU compositions at the site of intended use.

Suitable salts of glyphosate include monobasic, dibasic, or tribasicsalts and include organic amines, alkali metal, alkaline earth metal,ammonium (e.g., monoammonium, diammonium, or triammonium) and sulfonium(e.g., monosulfonium, disulfonium, or trimethylsulfonium (“TMS”) saltsof glyphosate. The organic amine salts can comprise aliphatic oraromatic amine salts and can include primary, secondary, tertiary, orquaternary amine salts. Specific representative examples of such organicamine salts include isopropylamine (“IPA”), n-propylamine, ethylamine,dimethylamine (“DMA”), monoethanolamine (“MEA”), ethylenediamine andhexamethylenediamine salts of glyphosate. Specific representativeexamples of alkali metal salts include potassium and sodium salts ofglyphosate. In accordance with more preferred embodiments of theinvention, the glyphosate component predominantly comprises a salt ofglyphosate selected from the potassium, monoammonium, diammonium,sodium, MEA, n-propylamine, IPA, ethylamine, DMA, ethylenediamine,hexamethylenediamine and TMS salts and combinations thereof. Of these,the MEA, diammonium, and potassium salts and combinations thereof areespecially preferred.

Previous studies have indicated that the various salts of glyphosatehave considerable differences in their compatibility with surfactants.In some instances, it has been shown that the potassium salt ofglyphosate is advantageous due to the high solubility in water and theresulting high density that allows for higher loading of the active informulations. However, potassium glyphosate offers limited compatibilitywith common surfactants used with glyphosate, for example, tertiaryamine ethoxylates. One aspect of the current invention is, therefore,the capability of amidoalkyl amine surfactants to improve compatibilityof potassium glyphosate with surfactants in a high load glyphosateformulation. The use of amidoalkylamine surfactants enables thepreparation of glyphosate formulations with higher active and surfactantloadings, as well as increased levels of ethoxylation of tertiary aminesurfactants compared to other coupling agents.

It has also been observed that certain of the other salts of glyphosateare difficult to formulate at loadings of, for example, about 540 ga.e./L, or higher, such as about 600 g a.e./L and higher in combinationwith a surfactant component. The other salts of glyphosate have beenobserved to offer better compatibility with surfactants compared to thepotassium salt. For example, monoethanolamine (MEA) glyphosate has beenobserved to be more compatible with a wider variety of surfactants,particularly ethoxylated tertiary amines. However, the limitedsolubility and density of the MEA salt of glyphosate is a limitingfactor in the formulation of a liquid herbicidal concentrate. In thisregard, blends of two or more salts of glyphosate may allow for thepreparation of highly loaded formulations containing amidoalkylaminecoupling agents blended with a primary surfactant at higher levels thanwhen formulated with potassium salt of glyphosate alone.

In some embodiments, the herbicidal composition of the present inventioncomprises a blend of the potassium salt of glyphosate and the ammoniumsalt of glyphosate. In other embodiments, the herbicidal composition ofthe present invention comprises a blend of the potassium salt ofglyphosate and the monoethanolamine salt of glyphosate. The weight ratioof the potassium salt of glyphosate in grams acid equivalent to themonoethanolamine salt of glyphosate in grams acid equivalent may bebetween about 1:1 to about 4:1, such as about 7:3. In some preferredembodiments, the weight ratio of the potassium salt of glyphosate ingrams acid equivalent to the monoethanolamine salt of glyphosate ingrams acid equivalent is about 7:3, which enables weight ratios ofethoxylated tertiary amine surfactants in grams to amido alkylaminecoupling agents in grams to vary from at least about 60:40, to at leastabout 65:35, and in some cases to at least about 70:30.

The herbicidal compositions of the present invention can be formulatedas aqueous solutions. The term “aqueous,” as used herein, refers tocompositions comprising water in an amount that renders it thepredominant solvent. “Aqueous” is not intended to exclude the presenceof nonaqueous (i.e., organic) solvents, as long as water is present.Examples of suitable nonaqueous solvents include toluene, xylenes,petroleum naphtha, tetrahydrofurfuryl alcohol, ethylene glycol,polyethylene glycol, propylene glycol, ethanol, and hexanol.

The concentration of the glyphosate component in an aqueous herbicidalconcentrate according to the present invention is typically at leastabout 300 grams acid equivalent per liter (“g a.e./L”), such as at leastabout 360 g a.e./L, such as at least about 390 g a.e./L. In preferredcompositions of the invention, glyphosate concentration is not lowerthan 400 g a.e./L or about 420 g a.e./L, in particularly preferredcompositions not lower than about 480 g a.e./L, or even about 540 ga.e./L, for example about 480 to about 540 g a.e./L, or about 480 toabout 600 g a.e./L, or more. Accordingly, the concentration of theglyphosate component in a herbicidal concentrate is typically betweenabout 300 g a.e./L and about 600 g a.e./L, preferably between about 420g a.e./L and about 600 g a.e./L, even more preferably between about 480g a.e./L and about 540 g a.e./L. It is believed that the upper limit ofglyphosate concentration in a storage-stable surfactant-containingcomposition of the invention is in excess of about 650 g a.e./L, e.g.,to about 700 g a.e./L, this limit being a consequence of the solubilitylimit of glyphosate and glyphosate salts in water, compounded by furtherlimitation due to the presence of surfactant.

The solid concentrate compositions of the invention preferably compriseglyphosate or a derivative thereof in a concentration of greater than30% by weight acid equivalent of the composition, such as from about 30%to about 90% by weight acid equivalent of the composition, such as fromabout 40% to about 90% by weight acid equivalent of the composition,more preferably from about 50% to about 80% by weight acid equivalent ofthe composition.

The present invention is further directed to RTU formulations preparedby diluting herbicidal concentrates with appropriate amounts of water.The concentration of the glyphosate component in aqueous RTUcompositions of the present invention is typically at least about 1 ga.e./L, and generally from about 1 g a.e./L to about 50 g a.e./L. Inorder to provide more economical RTU formulations providing prolongedherbicidal activity, the concentration of the glyphosate component inthe RTU composition is more preferably from about 5 g a.e./L to about 20g a.e./L.

The compositions of the present invention comprise one or moreamidoalkylamine surfactants added to the formulation to enhance thestability of high load glyphosate concentrates and to enhance thebioefficacy when combined with at least one other co-surfactant. Theamidoalkylamine surfactants have the general structure (I):

wherein R₁ is a hydrocarbyl or substituted hydrocarbyl having from 1 toabout 22 carbon atoms, R₂ and R₃ are each independently hydrocarbyl orsubstituted hydrocarbyl having from 1 to about 6 carbon atoms and R₄ ishydrocarbylene or substituted hydrocarbylene having from 1 to about 6carbon atoms.

R₁ is preferably an alkyl or substituted alkyl having an average valueof carbon atoms between about 4 to about 20 carbon atoms, preferably anaverage value between about 4 and about 18 carbon atoms, more preferablyan average value from about 4 to about 12 carbon atoms, more preferablyan average value from about 5 to about 12 carbon atoms, even morepreferably an average value from about 6 to about 12 carbon atoms, andstill more preferably an average value from about 6 to about 10 carbonatoms. The R₁ alkyl group may be derived from a variety of sources thatprovide alkyl groups having from about 4 to about 18 carbon atoms, forexample, the source may be butyric acid, valeric acid, caprylic acid,capric acid, coco (comprising mainly lauric acid), myristic acid (from,e.g., palm oil), soy (comprising mainly linoleic acid, oleic acid, andpalmitic acid), or tallow (comprising mainly palmitic acid, oleic acid,and stearic acid). In some embodiments, the amidoalkylamine surfactantcomponent may comprise a blend of amidoalkylamines having alkyl chainsof various lengths from about 5 carbon atoms to about 12 carbon atoms.For example, depending upon the source of the R₁ alkyl group, anamidoalkylamine surfactant component may comprise a blend of surfactantshaving R₁ groups that are 5 carbon atoms in length, 6 carbon atoms inlength, 7 carbon atoms in length, 8 carbon atoms in length, 9 carbonatoms in length, 10 carbon atoms in length, 11 carbon atoms in length,and 12 carbon atoms in length, longer carbon chains, and combinationsthereof. In other embodiments, the amidoalkylamine surfactant componentmay comprise a blend of surfactants having R₁ groups that are 5 carbonatoms in length, 6 carbon atoms in length, 7 carbon atoms in length, and8 carbon atoms in length. In some alternative embodiments, theamidoalkylamine surfactant component may comprise a blend of surfactantshaving R₁ groups that are 6 carbon atoms in length, 7 carbon atoms inlength, 8 carbon atoms in length, 9 carbon atoms in length, and 10carbon atoms in length. In other embodiments, the amidoalkylaminesurfactant component may comprise a blend of surfactants having R₁groups that are 8 carbon atoms in length, 9 carbon atoms in length, 10carbon atoms in length, 11 carbon atoms in length, and 12 carbon atomsin length.

R₂ and R₃ are independently preferably an alkyl or substituted alkylhaving from 1 to about 4 carbon atoms. R₂ and R₃ are most preferablyindependently an alkyl having from 1 to about 4 carbon atoms, and mostpreferably methyl. R₄ is preferably an alkylene or substituted alkylenehaving from 1 to about 4 carbon atoms. R₄ is most preferably an alkylenehaving from 1 to about 4 carbon atoms, and most preferably n-propylene.

In one preferred amidoalkylamine surfactant, R₁ is C₆₋₁₀, i.e., an alkylgroup having 6 carbon atoms, 7 carbon atoms, 8 carbon atoms, 9 carbonatoms, 10 carbon atoms, or a blend of any of these, i.e., from about 6carbon atoms to about 10 carbon atoms; R₂ and R₃ are each methyl; and R₄is n-propylene (i.e., C₆₋₁₀ amidopropyl dimethylamine).

Based on experimental evidence to date, amidoalkylamine surfactantshaving the general structure (I) have been shown to be compatible withthe various water soluble salts of glyphosate, particularly potassium,isopropylammonium, ammonium, monoethanolamine, and diammonium salts ofglyphosate, and combinations of glyphosate salts, such as a blend ofpotassium glyphosate and monoethanolamine glyphosate, or a blend ofpotassium glyphosate and ammonium glyphosate. Moreover, amidoalkylaminesurfactants having the general structure (I) have been discovered toenhance the stability of highly loaded glyphosate formulations whencoupled with, for example, alkoxylated tertiary amine co-surfactants,alkoxylated quaternary amine co-surfactants, and a variety of additionalco-surfactants, as measured by cloud point and long term stabilitystudies. The amidoalkylamine surfactants have also been shown to enhancethe stability of tank-mixed, ready to use formulations that are combinedwith co-herbicides. The amidoalkylamine surfactants have also been shownto enhance the bioefficacy of glyphosate formulations when coupled with,for example, alkoxylated tertiary amine co-surfactants, alkoxylatedquaternary amine co-surfactants, or any of a wide variety of otherco-surfactants. Finally, the use of amidoalkylamines within a surfactantblend advantageously reduces eye and skin toxicity of the herbicidalconcentrates of the present invention compared to surfactants that arecurrently used in commercially available glyphosate products.

In herbicidal compositions of the present invention, the above-describedamidoalkylamine surfactant acts a coupling agent in combination with anadditional surfactant component. In some embodiments, the additionalsurfactant component is selected from among an alkoxylated tertiaryamine, an alkoxylated quaternary amine, or a combination thereof.

Alkoxylated tertiary amine co-surfactants of the present invention havethe general structure (II):

wherein R₁ is a hydrocarbyl or substituted hydrocarbyl having from about4 to about 22 carbon atoms, R₂ and R₃ are each independentlyhydrocarbylene having 2, 3, or 4 carbon atoms (e.g., ethylene, propyleneor isopropylene), and the sum of x and y is an average value rangingfrom about 2 to about 50.

R₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, and still morepreferably from about 12 to about 18 carbons atoms, for example coco ortallow. R₁ is most preferably tallow. R₂ and R₃ are preferably ethylene.The sum of x and y is preferably an average value ranging from about 2to about 22, more preferably between about 10 and about 20, for example,about 15.

Specific alkoxylated tertiary amine co-surfactants for use in theherbicidal compositions of the present invention include, for example,Ethomeen T/12, Ethomeen T/20, Ethomeen T/25, Ethomeen T/30, EthomeenT/60, Ethomeen C/12, Ethomeen C/15, and Ethomeen C/25, each of which areavailable from Akzo Nobel.

Alkoxylated quaternary amine co-surfactants of the present inventionhave the general structure (III):

wherein R₁, R₂, R₃, x and y are as described above for the alkoxylatedtertiary amine co-surfactants of structure (II), i.e., R₁ is ahydrocarbyl or substituted hydrocarbyl having from about 4 to about 22carbon atoms, R₂ and R₃ are each independently hydrocarbylene having 2,3, or 4 carbon atoms (e.g., ethylene, propylene or isopropylene), andthe sum of x and y is an average value ranging from about 2 to about 50.R₄ is preferably a hydrocarbyl or substituted hydrocarbyl having from 1to about 4 carbon atoms, more preferably methyl. X is a charge balancingcounter-anion, such as sulfate, chloride, bromide, nitrate, amongothers.

R₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, and still morepreferably from about 12 to about 18 carbons atoms, for example coco ortallow. R₁ is most preferably tallow. R₂ and R₃ are preferably ethylene.The sum of x and y is preferably an average value ranging from about 2to about 22, more preferably between about 10 and about 20, for example,about 15.

Specific alkoxylated quaternary amine co-surfactants for use in theherbicidal composition of the present invention include, for example,Ethoquad T/12, Ethoquad T/20, Ethoquad T/25, Ethoquad C/12, EthoquadC/15, and Ethoquad C/25, each of which are available from Akzo Nobel.

With regard to the surfactant blend itself, the use of theamidoalkylamine surfactant as a coupling agent enables the preparationof high load glyphosate herbicidal concentrates with higher proportionsof alkoxylated tertiary amine co-surfactants and alkoxylated quaternaryamine co-surfactants of improved stability compared to formulationscomprising conventional coupling agents. Stated another way, increasingthe proportion of the alkoxylated tertiary amine co-surfactants andalkoxylated quaternary amine co-surfactants normally decreases thestability of a high load glyphosate formulation when a conventionalcoupling agent is employed. The amidoalkylamine coupling agent enablesthe preparation of high load glyphosate formulations having higherproportions of alkoxylated tertiary amine co-surfactants and alkoxylatedquaternary amine co-surfactants that are stable as illustrated by longterm storage stability and cloud point studies. With regard to thesurfactant blend, a concentration ratio of the amidoalkylaminesurfactant in g/L to any of (1) the alkoxylated tertiary amineco-surfactant in g/L, (2) the alkoxylated quaternary amine co-surfactantin g/L, or (3) the sum of the combination of the alkoxylated tertiaryamine co-surfactant and the alkoxylated quaternary amine co-surfactantin g/L may vary from 10:1 to about 1:10, more preferably from 8:1 toabout 1:8, more preferably from 5:1 to about 1:5, and most preferablyfrom 2:1 to about 1:2. Preferably, the concentration ratio of theamidoalkylamine surfactant in g/L to any of (1) the alkoxylated tertiaryamine co-surfactant in g/L, (2) the alkoxylated quaternary amineco-surfactant in g/L, or (3) the sum of the combination of thealkoxylated tertiary amine co-surfactant and the alkoxylated quaternaryamine co-surfactant in g/L is less than about 45:55, more preferablyless than about 40:60, even more preferably less than about 35:65.

The pH of the herbicidal composition of the present invention is afactor in stability, cloud point, compatibilization of glyphosate saltswith the surfactants used, and compatibilization with co-herbicides, ifadded. In this regard, the pH of an herbicidal composition comprisingpotassium glyphosate, for example, as its predominant glyphosatecomponent may be from about 4 to about 8, such as from about 4.5 toabout 5.5. In other embodiments, the pH of a herbicidal compositioncomprising diammonium glyphosate as its predominant glyphosate componentmay be from about 4 to about 8, such as from about 5 to about 7, such asfrom about 5.5 to about 6.5.

pH adjusting agents for acidic adjustment include mineral acids such as,for example, hydrochloric acid, nitric acid or sulfuric acid, andorganic acids such as, for example, acetic acid or dicarboxylic acids.pH adjusting agents for alkaline adjustment include, for example, sodiumhydroxide, potassium hydroxide, ammonia, and organic bases, such as IPA,MEA, and DMA.

The herbicidal compositions may further comprise other conventionaladjuvants, excipients, or additives known to those skilled in the art.These other additives or ingredients may be introduced into thecompositions of the present invention to provide or improve certaindesired properties or characteristics of the formulated product. Hence,the herbicidal composition may further comprise one or more additionalingredients selected from, without limitation, foam-moderating agents,surfactants, preservatives or anti-microbials, antifreeze agents,solubility-enhancing agents, dyes, pH adjusters and thickening agents.

Suitable surfactants are known to those skilled in the art and includecationic, nonionic, and anionic surfactants. These surfactants may beincluded in the herbicidal compositions of the present invention so longas they do not adversely affect the stability or compatibility of thesurfactant component with the remainder of the glyphosate formulation.In some instances, the herbicidal compositions of the present inventioncomprise glyphosate or a glyphosate derivative, an amidoalkylaminecoupling agent, and at least one of a compatible cationic, nonionic, oranionic co-surfactant. In other instances, the herbicidal compositionsof the present invention comprise glyphosate or a glyphosate derivative,an amidoalkylamine coupling agent, an additional surfactant componentselected from among an alkoxylated tertiary amine, an alkoxylatedquaternary amine, or a combination thereof, and at least one of acompatible cationic, nonionic, or anionic co-surfactant. The herbicidalcompositions of the present invention may also comprise glyphosate or aglyphosate derivative, an amidoalkylamine coupling agent, and at leastone of a compatible cationic, nonionic, or anionic co-surfactant.

Suitable classes of cationic surfactants include primary, secondary andtertiary alkylamines, primary, secondary and tertiary alkylaminium saltsin which an amine group is substantially protonated in the formulation,onium salts such as quaternary alkylammonium salts, and mixturesthereof. A wide variety of primary, secondary, tertiary, quaternary andzwitterionic alkylamine and alkylammonium salt surfactants can beutilized in the practice of the present invention. A subclasses ofprimary, secondary, and tertiary alkylamine surfactants for use in thepresent invention are alkyl amine oxides, alkyletheramines, andalkyletheramine oxides as disclosed in U.S. Pat. No. 5,750,468 (toWright).

In some embodiments, herbicidal compositions of the present inventioncomprise an amidoalkylamine surfactant as a coupling agent for aco-surfactant component selected from among alkoxylated tertiaryetheramine surfactants or alkoxylated quaternary etheramine surfactants.

Alkoxylated tertiary etheramine co-surfactant for use in the herbicidalcompositions of the present invention have the general structure (IV):

wherein R₁ is a hydrocarbyl or substituted hydrocarbyl having from about4 to about 22 carbon atoms; R₂, R₃ and R₄ are each independently ahydrocarbylene having 2, 3, or 4 carbon atoms (e.g., ethylene, propyleneor isopropylene); m is an average number from about 1 to about 10; andthe sum of x and y is an average value ranging from about 2 to about 60.

R₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, from about 10 toabout 16 carbon atoms, from about 12 to about 18 carbons atoms, or fromabout 10 to about 14 carbon atoms. Sources of the R₁ group include, forexample, coco or tallow, or R₁ may be derived from synthetichydrocarbyls, such as decyl, dodedecyl, tridecyl, tetradecyl, hexadecyl,or octadecyl groups. M is preferably from about 1 to 5, such as 2 to 3.R₂, R₃ and R₄ may independently be ethylene, propylene, isopropylene,and are preferably ethylene. The sum of x and y is preferably an averagevalue ranging from about 2 to about 22, such as from about 2 to 10, orabout 2 to 5. In some embodiments, the sum of x and y is preferablybetween about 10 and about 20, for example, about 15.

Specific alkoxylated tertiary etheramine co-surfactants for use in theherbicidal composition of the present invention include, for example,any of the TOMAH E-Series surfactants, such as TOMAH E-14-2, TOMAHE-14-5, TOMAH E-17-2, TOMAH E-17-5, TOMAH E-19-2, TOMAH E-18-2, TOMAHE-18-5, TOMAH E-18-15, TOMAH E-S-2, TOMAH E-S-15, TOMAH E-T-2, TOMAHE-T-5, and TOMAH E-T-15, all available from Air Products and Chemicals,Inc. Another example is SURFONIC AGM 550 available from HuntsmanPetrochemical Corporation.

Alkoxylated quaternary etheramine co-surfactants for use in theherbicidal compositions of the present invention have the generalstructure (V):

wherein R₁ is a hydrocarbyl or substituted hydrocarbyl having from about4 to about 22 carbon atoms; R₂, R₃ and R₄ are each independently is ahydrocarbylene having 2, 3, or 4 carbon atoms (e.g., ethylene, propyleneor isopropylene); m is an average number from about 1 to about 10; andthe sum of x and y is an average value ranging from about 2 to about 60.R₅ is preferably a hydrocarbyl or substituted hydrocarbyl having from 1to about 4 carbon atoms, more preferably methyl. A is a charge balancingcounter-anion, such as sulfate, chloride, bromide, nitrate, amongothers.

R₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, from about 10 toabout 16 carbon atoms, from about 12 to about 18 carbons atoms, or fromabout 12 to about 14 carbon atoms. Sources of the R₁ group include, forexample, coco or tallow, or R₁ may be derived from synthetichydrocarbyls, such as decyl, dodedecyl, tridecyl, tetradecyl, hexadecyl,or octadecyl groups. M is preferably from about 1 to 5, such as 2 to 3.R₂, R₃ and R₄ may independently be ethylene, propylene, isopropylene,and are preferably ethylene. R₅ is preferably methyl. The sum of x and yis preferably an average value ranging from about 2 to about 22, such asfrom about 2 to 10, or about 2 to 5. In some embodiments, the sum of xand y is preferably between about 10 and about 20, for example, about15.

Specific alkoxylated quaternary etheramine co-surfactants for use in theherbicidal composition of the present invention include, for example,TOMAH Q-14-2, TOMAH Q-17-2, TOMAH Q-17-5, TOMAH Q-18-2, TOMAH Q-S, TOMAHQ-S-80, TOMAH Q-D-T, TOMAH Q-DT-HG, TOMAH Q-C-15, and TOMAH Q-ST-50, allavailable from Air Products and Chemicals, Inc.

Preferred subclasses of zwitterionic or amphoteric alkylammonium saltsfor use in the present invention are amino acid derivatives such asalkyl, dialkyl or alkyl lower-alkyl glycines, beta-alanines, aspartates,and the like. Preferred alkylammonium salts are quaternary alkylammoniumsalts. Classes of quaternary alkylammonium salts useful in the presentinvention include quaternized (e.g., N-methyl) alkylamines, quaternizedpolyoxyalkylene alkylamines, quaternary salts of pyridines, quaternarysalts of carboxylated imidazolines (open and closed chain) and trialkylbetaines. Trialkylamine oxides are a class of compounds which formquaternary ammonium hydroxide salts upon addition to water and are alsouseful in the practice of the present invention. Other general classesof quaternary alkylammonium and alkylaminium salt surfactants useful inthe practice of the present invention will be known to and readilyascertainable by those skilled in the art.

Nonionic surfactants suitable for the practice of the present inventioninclude, without restriction, polyoxyalkylene primary and secondaryC₈₋₂₀ alkylethers, alkoxylated acetylenic diols, polyoxyalkylene mono-and di(C₈₋₂₀ alkyl)phenylethers, polyoxyalkylene di- andtristyrylphenylethers, polyoxyalkylene C₈₋₂₀ fatty acid esters,alkoxylated alcohols such as polyoxyalkylene C₈₋₂₀ alcohols, alkoxylatedvegetable oils, alkoxylated castor oil, block copolymers of ethyleneoxide and propylene oxide and C₂₋₆ alkyl adducts thereof, glycerol fattyacid esters, sorbitan C₈₋₂₀ mono-, di- and tri(C₈₋₂₀ fatty acid) esters,polyoxyalkylene sorbitan mono-, di- and tri(C₈₋₂₀ fatty acid) esters,sucrose esters, C₈₋₂₀ alkyl polyglycosides, alkoxylated etheramine oxidesurfactants, and alkoxylated tertiary amine oxide surfactants.

In some instances, herbicidal compositions of the present inventioncomprise an amidoalkylamine surfactant as a coupling agent for aco-surfactant component selected from among alkoxylated etheramine oxideco-surfactants or alkoxylated tertiary amine oxide co-surfactants.

Alkoxylated etheramine oxide co-surfactants for use in the herbicidalcompositions of the present invention have the general structure (VI):

wherein R₁ is a hydrocarbyl or substituted hydrocarbyl having from about4 to about 22 carbon atoms; R₂, R₃ and R₄ are each independently ahydrocarbylene having 2, 3, or 4 carbon atoms (e.g., ethylene, propyleneor isopropylene); m is an average number from about 1 to about 10; andthe sum of x and y is an average value ranging from about 2 to about 60.

R₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, from about 10 toabout 16 carbon atoms, from about 12 to about 18 carbons atoms, or fromabout 12 to about 14 carbon atoms. Sources of the R₁ group include, forexample, coco or tallow, or R₁ may be derived from synthetichydrocarbyls, such as decyl, dodedecyl, tridecyl, tetradecyl, hexadecyl,or octadecyl groups. M is preferably from about 1 to 5, such as 2 to 3.R₂, R₃ and R₄ may independently be ethylene, propylene, isopropylene,and are preferably ethylene. The sum of x and y is preferably an averagevalue ranging from about 2 to about 22, such as from about 2 to 10, orabout 2 to 5. In some embodiments, the sum of x and y is preferablybetween about 10 and about 20, for example, about 15.

Specific alkoxylated etheramine oxide co-surfactants for use in theherbicidal composition of the present invention include, for example,any of the TOMAH AO-series of surfactants, such as TOMAH AO-14-2, TOMAHAO-728, TOMAH AO-17-7, TOMAH AO-405, and TOMAH AO-455, all availablefrom Air Products and Chemicals, Inc.

Alkoxylated tertiary amine oxide co-surfactants of the present inventionhave the general structure (VII):

wherein R₁ is a hydrocarbyl or substituted hydrocarbyl having from about4 to about 22 carbon atoms, R₂ and R₃ are each independentlyhydrocarbylene having 2, 3, or 4 carbon atoms (e.g., ethylene, propyleneor isopropylene), and the sum of x and y is an average value rangingfrom about 2 to about 50.

R₁ is preferably an alkyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 18 carbon atoms, and still morepreferably from about 12 to about 18 carbons atoms, for example coco ortallow. R₁ is most preferably tallow. R₂ and R₃ are preferably ethylene.The sum of x and y is preferably an average value ranging from about 2to about 22, more preferably between about 10 and about 20, for example,about 15.

Specific alkoxylated tertiary amine oxide co-surfactants for use in theherbicidal compositions of the present invention include, for example,any of the AROMOX series of surfactants, including AROMOX C/12, AROMOXC/12W, AROMOX DMC, AROMOX DM16, AROMOX DMHT, and AROMOX T/12 DEG, allavailable from Akzo Nobel.

In some instances, herbicidal compositions of the present inventioncomprise an amidoalkylamine surfactant as a coupling agent for analkoxylated alcohol surfactant co-surfactant component.

Alkoxylated alcohol co-surfactants of the present invention may have thegeneral structure (VIII):

R₁—O—(R₂O)_(n)H  Structure (VIII)

wherein R₁ is a hydrocarbyl or substituted hydrocarbyl having from about4 to about 22 carbon atoms; R₂ is a hydrocarbylene having 2, 3, or 4carbon atoms (e.g., ethylene, propylene or isopropylene); and n is anaverage value ranging from about 2 to about 50.

R₁ is preferably an alkyl group having from about 4 to about 22 carbonatoms, more preferably from about 8 to about 18 carbon atoms, and stillmore preferably from about 12 to about 18 carbons atoms. R₁ may bebranched or linear. Preferably, R₁ is linear. The R₁ alkyl group may bederived from a variety of sources that provide alkyl groups having fromabout 4 to about 22 carbon atoms, for example, the source may be butyricacid, valeric acid, caprylic acid, capric acid, coco (comprising mainlylauric acid), myristic acid (from, e.g., palm oil), soy (comprisingmainly linoleic acid, oleic acid, and palmitic acid), or tallow(comprising mainly palmitic acid, oleic acid, and stearic acid). Sourcesof the R₁ group include, for example, coco or tallow, or R₁ may bederived from synthetic hydrocarbyls, such as decyl, dodedecyl, tridecyl,tetradecyl, hexadecyl, or octadecyl groups. The R₁ alkyl chain in apopulation of alkoxylated alcohol co-surfactants typically comprisesalkyl chains having varying length, for example, from 12 to 16 carbonsin length, or from 16 to 18 carbons in length, on average. Mostpreferably, the R₁ alkyl chain comprises predominantly 12 to 16 carbonatoms. R₂ is preferably ethylene. The value of n is preferably anaverage between about 2 and about 30, more preferably between about 2and about 20, even more preferably between about 2 and about 10.

Specific alkoxylated alcohol co-surfactants for use in the herbicidalcompositions of the present invention include, for example, Ethylan 6830available from Akzo Nobel or Surfonic L24-7 and Surfonic L12-8 availablefrom Huntsman.

Anionic surfactants useful as components of the stabilizing system ofcompositions of the include, without restriction, C₈₋₂₀ alkylcarboxylates including fatty acids, C₈₋₂₀ alcohol sulfates, phosphateesters of alkoxylated tertiary amines, phosphate esters of alkoxylatedetheramines, phosphate esters of alkoxylated alcohols such as C₈₋₂₀alcohol phosphate mono- and diesters, C₈₋₂₀ alcohol and (C₈₋₂₀alkyl)phenol polyoxyethylene ether carboxylates, sulfates andsulfonates, C₈₋₂₀ alcohol and (C₈₋₂₀ alkyl) phenol polyoxyethylenephosphate mono- and diesters, C₈₋₂₀ alkylbenzene sulfonates, naphthalenesulfonates and formaldehyde condensates thereof, lignosulfonates, C₈₋₂₀alkyl sulfosuccinates and sulfosuccinamates, C₈₋₂₀ alkyl polyoxyethylenesulfosuccinates and sulfosuccinamates, and C₈₋₂₀ acyl glutamates,sarcosinates, isethionates and taurates.

In some embodiments, herbicidal compositions of the present inventioncomprise an amidoalkylamine surfactant as a coupling agent for aco-surfactant component selected from among phosphate esters ofalkoxylated tertiary amine co-surfactants or phosphate esters ofalkoxylated etheramine co-surfactants.

Phosphate esters of alkoxylated tertiary amine co-surfactants for use inthe herbicidal compositions of the present invention have the generalstructures (Ixa) and (Ixb):

wherein each R₁ is independently a hydrocarbyl or substitutedhydrocarbyl having from about 4 to about 22 carbon atoms, R₂ and R₃ areeach independently hydrocarbylene having 2, 3, or 4 carbon atoms (e.g.,ethylene, propylene or isopropylene), the sum of each x and y group isan average value ranging from about 2 to about 60, and R₄ and R₅ areeach independently hydrogen or a linear or branched chain hydrocarbyl orsubstituted hydrocarbyl having from 1 to about 6 carbon atoms.

Each R₁ is preferably independently an alkyl having from about 4 toabout 22 carbon atoms, more preferably from about 8 to about 18 carbonatoms, and still more preferably from about 12 to about 18 carbonsatoms, for example coco or tallow. R₁ is most preferably tallow. Each R₂and R₃ is preferably ethylene. The sum of each x and y group ispreferably independently an average value ranging from about 2 to about22, more preferably between about 10 and about 20, for example, about15. More preferably R₄ and R₅ are each independently hydrogen or alinear or branched chain alkyl having from 1 to about 6 carbon atoms. R₄and R₅ are preferably hydrogen.

Specific phosphate esters of alkoxylated tertiary amine co-surfactantsfor use in the herbicidal composition of the present invention aredescribed in U.S. 2002/0160918, by Lewis et al. (Huntsman PetrochemicalCorporation), such as phosphate esters of tallow amine ethoxylates,including ‘phosphate esters of SURFONIC® T5, phosphate esters ofSURFONIC® T15, phosphate esters of SURFONIC® T20, and mixtures thereof,all available from Huntsman International LLC.

Phosphate esters of alkoxylated etheramine co-surfactants for use in theherbicidal compositions of the present invention have the generalstructures (Xa) and (Xb):

wherein each R₁ is independently a hydrocarbyl or substitutedhydrocarbyl having from about 4 to about 22 carbon atoms; each R₂, R₃and R₄ is independently a hydrocarbylene having 2, 3, or 4 carbon atoms(e.g., ethylene, propylene or isopropylene); each m is independently anaverage number from about 1 to about 10; the sum of each x and y groupis independently an average value ranging from about 2 to about 60; andeach R₅ and R₆ are independently hydrogen or a linear or branched chainalkyl having from 1 to about 6 carbon atoms.

Each R₁ is preferably independently an alkyl having from about 4 toabout 22 carbon atoms, more preferably from about 8 to about 18 carbonatoms, from about 10 to about 16 carbon atoms, from about 12 to about 18carbons atoms, or from about 12 to about 14 carbon atoms. Sources of theR₁ group include, for example, coco or tallow, or R₁ may be derived fromsynthetic hydrocarbyls, such as decyl, dodedecyl, tridecyl, tetradecyl,hexadecyl, or octadecyl groups. Each R₂ may independently be propylene,isopropylene, or ethylene, and each m is preferably independently fromabout 1 to 5, such as 2 to 3. Each R₃ and R₄ may independently beethylene, propylene, isopropylene, and are preferably ethylene. The sumof each x and y group is preferably independently an average valueranging from about 2 to about 22, such as from about 2 to 10, or about 2to 5. In some embodiments, the sum of each x and y group is preferablyindependently between about 10 and about 20, for example, about 15. Morepreferably R₅ and R₆ are each independently hydrogen or a linear orbranched chain alkyl having from 1 to about 6 carbon atoms. R₅ and R₆are preferably hydrogen.

Phosphate esters of alkoxylated alcohol co-surfactants for use in theherbicidal compositions of the present invention have the generalstructures (XIa) and (XIb):

wherein each R₁ is independently a hydrocarbyl or substitutedhydrocarbyl having from about 4 to about 22 carbon atoms; each R₂ isindependently a hydrocarbylene having 2, 3, or 4 carbon atoms (e.g.,ethylene, propylene or isopropylene); each m is independently an averagenumber from about 1 to about 60; and R₃ and R₄ are each independentlyhydrogen or a linear or branched chain alkyl having from 1 to about 6carbon atoms.

Each R₁ is preferably independently an alkyl having from about 4 toabout 22 carbon atoms, more preferably from about 8 to about 20 carbonatoms, or an alkylphenyl having from about 4 to about 22 carbon atoms,more preferably from about 8 to about 20 carbon atoms. Sources of the R₁group include, for example, coco or tallow, or R₁ may be derived fromsynthetic hydrocarbyls, such as decyl, dodedecyl, tridecyl, tetradecyl,hexadecyl, or octadecyl groups. Each R₂ may independently be propylene,isopropylene, or ethylene, and is preferably ethylene. Each m ispreferably independently from about 9 to about 15. More preferably R₃and R₄ are each independently hydrogen or a linear or branched chainalkyl having from 1 to about 6 carbon atoms. R₄ and R₅ are preferablyhydrogen.

Specific phosphate esters of alkoxylated alcohol co- surfactants for usein the herbicidal composition of the present invention include, forexample, EMPHOS CS-121, EMPHOS PS-400, and WITCONATE D-51-29, availablefrom Akzo Nobel.

In aqueous concentrate and RTU compositions of the present invention, aconcentration ratio of the glyphosate in grams acid equivalent (“ga.e./L”) to the surfactant component in g/L of from about 1:1 to about50:1 is preferred, more preferably from about 2:1 to about 20:1, morepreferably from about 2:1 to about 10:1, more preferably from about 3:1to about 10:1, and most preferably from about 3:1 to about 5:1, such asabout 4:1. In aqueous concentrates of the present invention, totalsurfactant loadings of about 120 g/L to about 150 g/L, such as about 135g/L, can be attained in compositions containing glyphosate salt loadingsof about 480 g a.e./L to about 600 g a.e./L, such as about 540 g/L. Theweight ratio of glyphosate to surfactant component is important from thestandpoints of enhanced bioefficacy, compatibility, and long termstorage stability.

In solid concentrate compositions of the present invention, a weightratio of glyphosate in grams acid equivalent (“g a.e.”) to the totalsurfactant component in grams may generally vary from about 1:1 to about50:1, preferably from about 2:1 to about 20:1, more preferably fromabout 2:1 to about 10:1, more preferably from about 3:1 to about 10:1,and most preferably from about 3:1 to about 5:1, such as about 4:1.

With regard to the surfactant blend, a concentration ratio of theamidoalkylamine surfactant in g/L to any of above-described additionalsurfactants, alone or in combination with other surfactants, in g/L mayvary from 10:1 to about 1:10, more preferably from 8:1 to about 1:8,more preferably from 5:1 to about 1:5, and most preferably from 2:1 toabout 1:2. Preferably, the concentration ratio of the amidoalkylaminesurfactant in g/L to any of above-described additional surfactants,alone or in combination with other surfactants in g/L is less than about45:55, more preferably less than about 40:60, even more preferably lessthan about 35:65.

Suitable foam-moderating agents include silicone-based compositions. Anexample of a foam-moderating agent for compositions is SAG-10, availablefrom GE Silicones Corporation (Wilton, Conn.). The amount offoam-moderating agent optionally employed is that which is sufficient toinhibit and/or reduce an amount of foam that may otherwise be formedduring the process of preparing and containerizing the formulationand/or use thereof to a desired and satisfactory level. Generally, theconcentration of foam-moderating agent is in the range from about 0.001%up to about 0.05% by weight of the composition, and typically from about0.01% to about 0.03% by weight of the composition, although greater orlesser amounts may be employed.

The compositions may also comprise a preservative such as PROXEL GXLcontaining 1,2-benzisothiazolin-3-one (CAS No. 2634-33-5) available fromAvecia, Inc. (Wilmington, Del.), DOWICIL 150 containingcis-1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadmatane chloride (CAS No.051229-78-8) available from Dow Chemical Company (Midland, Mich.),NIPACIDE BIT20DPG containing benzisothiazolinone available from ClariantCorporation (Greensboro, N.C.), LEGEND MK anti-microbial biocideavailable from Rohm and Haas Co. (Philadelphia, Pa.), sorbic acid,mixtures thereof and the like in the range of from about 0.01% to about0.2% by weight, preferably about 0.1% by weight of the composition.

Suitable antifreeze agents include ethylene glycol and propylene glycoland generally may be present at a concentration of from about 0.1% toabout 10% by weight of the RTU composition. Antifreeze agents assist inlowering the freezing point of aqueous solutions and maintainingsolubility of the components of the composition such that components donot crystallize or precipitate during cycles of freezing and thawing.

Although the compositions of the present invention generally show goodoverall stability and viscosity properties without the addition of anyfurther additives, the addition of a solubility-enhancing agent (alsocommonly referred to as a cloud point enhancer or stabilizer) maysignificantly improve the properties of the formulations.Solubility-enhancing agents include polymer derivatives of ethyleneglycol and propylene glycol (e.g., 200-1200 average molecular weight),glycerol, sugars, mixtures thereof and the like in amounts up to about10%, preferably from about 0.05 to about 10% by weight, more preferablyfrom about 0.1 to about 1% by weight of the RTU composition.

The herbicidal compositions, i.e., liquid concentrates, solidconcentrates, and ready to use formulations may further comprise aco-herbicide. The amidoalkylamine surfactant enhances the solubility oftank-mixed herbicidal compositions that further comprise a co-herbicide.In some preferred embodiments, the herbicidal composition is a tankmixed ready to use formulation further comprising a co-herbicide, saidtank mixed ready to use formulation being more stable, i.e.,characterized by reduced agglomeration or precipitation of theco-herbicide, than conventional glyphosate formulations.

In some embodiments, water-soluble co-herbicides can be included in thecompositions of the present invention. Water-soluble co-herbicidesinclude acifluorfen, acrolein, amitrole, asulam, benazolin, bentazon,bialaphos, bromacil, bromoxynil, chloramben, chloroacetic acid,clopyralid, 2,4-D, 2,4-DB, dalapon, dicamba, dichlorprop, difenzoquat,diquat, endothall, fenac, fenoxaprop, flamprop, flumiclorac,fluoroglycofen, flupropanate, fomesafen, fosamine, glufosinate,imazameth, imazamethabenz, imazamox, imazapic, imazapyr, imazaquin,imazethapyr, ioxynil, MCPA, MCPB, mecoprop, methylarsonic acid,naptalam, nonanoic acid, paraquat, picloram, quinclorac, sulfamic acid,2,3,6-TBA, TCA, triclopyr and water-soluble salts thereof.

In some embodiments, co-herbicides that are not readily water-solublecan be coupled into the aqueous herbicidal composition by inclusion of asufficient quantity of an appropriate surfactant. In addition, thecompositions of the present invention may include finely-divided,water-insoluble herbicides. Examples of herbicides having limited watersolubility include, for example, acetochlor, aclonifen, alachlor,ametryn, amidosulfuron, anilofos, atrazine, azafenidin, azimsulfuron,benfluralin, benfuresate, bensulfuron-methyl, bensulide, benzofenap,bifenox, bromobutide, bromofenoxim, butachlor, butamifos, butralin,butroxydim, butylate, cafenstrole, carbetamide, carfentrazone-ethyl,chlomethoxyfen, chlorbromuron, chloridazon, chlorimuron-ethyl,chlornitrofen, chlorotoluron, chlorpropham, chlorsulfuron,chlorthal-dimethyl, chlorthiamid, cinmethylin, cinosulfuron, clethodim,clodinafop-propargyl, clomazone, clomeprop, cloransulam-methyl,cyanazine, cycloate, cyclosulfamuron, cycloxydim, cyhalofop-butyl,daimuron, desmedipham, desmetryn, dichlobenil, diclofop-methyl,diflufenican, dimefuron, dimepiperate, dimethachlor, dimethametryn,dimethenamid, dinitramine, dinoterb, diphenamid, dithiopyr, diuron,EPTC, esprocarb, ethalfluralin, ethametsulfuron-methyl, ethofumesate,ethoxysulfuron, etobenzanid, fenoxaprop-ethyl, fenuron, flamprop-methyl,flazasulfuron, fluazifop-butyl, fluchloralin, flumetsulam,flumiclorac-pentyl, flumioxazin, fluometuron, fluorochloridone,fluoroglycofen-ethyl, flupoxam, flurenol, fluridone,fluroxypyr-1-methylheptyl, flurtamone, fluthiacet-methyl, fomesafen,halosulfuron, haloxyfop-methyl, hexazinone, imazamox, imazosulfuron,indanofan, isoproturon, isouron, isoxaben, isoxaflutole, isoxapyrifop,lactofen, lenacil, linuron, mefenacet, mesotrione, metamitron,metazachlor, methabenzthiazuron, methyldymron, metobenzuron,metobromuron, metolachlor, metosulam, metoxuron, metribuzin,metsulfuron, molinate, monolinuron, naproanilide, napropamide, naptalam,neburon, nicosulfuron, norflurazon, orbencarb, oryzalin, oxadiargyl,oxadiazon, oxasulfuron, oxyfluorfen, pebulate, pendimethalin,pentanochlor, pentoxazone, phenmedipham, piperophos, pretilachlor,primisulfuron, prodiamine, prometon, prometryn, propachlor, propanil,propaquizafop, propazine, propham, propisochlor, propyzamide,prosulfocarb, prosulfuron, pyraflufen-ethyl, pyrazolynate,pyrazosulfuron-ethyl, pyrazoxyfen, pyributicarb, pyridate,pyriminobac-methyl, quinclorac, quinmerac, quizalofop-ethyl,rimsulfuron, sethoxydim, siduron, simazine, simetryn, sulcotrione,sulfentrazone, sulfometuron, sulfosulfuron, tebutam, tebuthiuron,terbacil, terbumeton, terbuthylazine, terbutryn, thenylchlor, thiazopyr,thifensulfuron, thiobencarb, tiocarbazil, tralkoxydim, triallate,triasulfuron, tribenuron, trietazine, trifluralin, triflusulfuron, andvernolate. Additional herbicidal active ingredient(s) in a concentrateor RTU formulation are present in an agriculturally useful concentrationthat will vary depending on the particular additional herbicide(s)selected for inclusion and is readily determined-by those skilled in theart.

The herbicidal concentrate of the present invention may be prepared bycombining the required amounts of glyphosate, water, amidoalkylaminesurfactant coupling agent, and the co-surfactant, with mixing using amechanical stirrer or any other suitable container or device producingthe necessary amount of agitation or circulation to thoroughly mix theingredients. The order of addition of the starting materials is notnarrowly critical to the stability of the final concentrate. In variousembodiments, the herbicidal concentrate is prepared according to anorder of component addition. Herein, water is preferably added to themixing vessel first, followed by the addition of the glyphosate salt.Next, the amidoalkylamine surfactant coupling agent is added, followedby the addition of the co-surfactant. In some embodiments, theco-surfactant may be added as a preblended mixture with theamidoalkylamine surfactant. In other embodiments, the co-surfactants maybe added singly, either before or after addition of the amidoalkylaminesurfactant.

A solid concentrate of the present invention may also be prepared bycombining the required amounts of glyphosate, amidoalkylamine surfactantcoupling agent, the co-surfactant, with mixing using a mechanicalstirrer, ball milling, or any other suitable container or deviceproducing the necessary amount of agitation or circulation to thoroughlymix the ingredients. The order of addition of the materials to preparethe solid concentrate is not narrowly critical to the stability of thefinal concentrate.

The RTU compositions of the present invention can be prepared bydiluting an aqueous herbicidal concentrate or dissolving a solidconcentrate with an appropriate amount of water.

The present invention is also directed to a method for killing orcontrolling weeds or other unwanted plants by spraying or otherwiseapplying a herbicidally effective amount of the RTU or dilutedconcentrate formulations described herein to the foliage of the plantsto be treated. The herbicidal spray compositions included in the presentinvention can be applied to the foliage of the plants to be treatedthrough any of the appropriate methods that are well known to thosehaving skill in the art. In some embodiments, the RTU composition ispackaged in a portable container suitable for hand carry by the user andfitted with an apparatus for manually releasing the composition from thecontainer onto the foliage of the plants to be treated in the form of aspray.

The compositions of the present invention can be used to kill or controlthe growth of a wide variety of plants. Particularly important annualdicotyledonous plant species include, without limitation, velvetleaf(Abutilon theophrasti), pigweed (Amaranthus spp.), buttonweed (Borreriaspp.), oilseed rape, canola, indian mustard, etc. (Brassica spp.),commelina (Commelina spp.), filaree (Erodium spp.), sunflower(Helianthus spp.), morningglory (Ipomoea spp.), kochia (Kochiascoparia), mallow (Malva spp.), wild buckwheat, smartweed, etc.(Polygonum spp.), purslane (Portulaca spp.), Russian thistle (Salsolaspp.), sida (Sida spp.), wild mustard (Sinapis arvensis) and cocklebur(Xanthium spp.).

Particularly important annual monocotyledonous plant species that may bekilled or controlled using the compositions of the present inventioninclude, without limitation, wild oat (Avena fatua), carpetgrass(Axonopus spp.), downy brome (Bromus tectorum), crabgrass (Digitariaspp.), barnyardgrass (Echinochloa crus-galli), goosegrass (Eleusineindica), annual ryegrass (Lolium multiflorum), rice (Oryza sativa),ottochloa (Ottochloa nodosa), bahiagrass (Paspalum notatum), canarygrass(Phalaris spp.), foxtail (Setaria spp.), wheat (Triticum aestivum) andcorn (Zea mays).

Particularly important perennial dicotyledonous plant species forcontrol of which a composition of the invention can be used include,without limitation, mugwort (Artemisia spp.), milkweed (Asclepias spp.),Canada thistle (Cirsium arvense), field bindweed (Convolvulus arvensis)and kudzu (Pueraria spp.).

Particularly important perennial monocotyledonous plant species forcontrol of which a composition of the invention can be used include,without limitation, brachiaria (Brachiaria spp.), bermudagrass (Cynodondactylon), quackgrass (Elymus repens), lalang (Imperata cylindrica),perennial ryegrass (Lolium perenne), guineagrass (Panicum maximum),dallisgrass (Paspalum dilatatum), reed (Phragmites spp.), johnsongrass(Sorghum halepense) and cattail (Typha spp.).

Other particularly important perennial plant species for control ofwhich a composition of the invention can be used include, withoutlimitation, horsetail (Equisetum spp.), bracken (Pteridium aquilinum),blackberry (Rubus spp.) and gorse (Ulex europaeus).

Suitable herbicidally efficacious application or spray rates used in thepractice of the present invention will vary depending on the particularcomposition and concentration of active ingredients, the desiredeffects, plant species treated, weather and other factors. Whatconstitutes a desired effect varies according to the standards andpractice of those who investigate, develop, market and use compositionsand the selection of application rates that are herbicidally effectivefor a composition of the invention is within the skill of those skilledin the art.

Definitions

The term “hydrocarbyl” as used herein describes organic compounds orradicals consisting exclusively of the elements carbon and hydrogen.These moieties include alkyl, alkenyl, alkynyl, and aryl moieties. Thesemoieties also include alkyl, alkenyl, alkynyl, and aryl moietiessubstituted with other aliphatic or cyclic hydrocarbon groups, such asalkaryl, alkenaryl and alkynaryl. Unless otherwise indicated, thesemoieties preferably comprise 1 to 30 carbon atoms.

The term “hydrocarbylene” as used herein describes radicals joined attwo ends thereof to other radicals in an organic compound, and whichconsist exclusively of the elements carbon and hydrogen. These moietiesinclude alkylene, alkenylene, alkynylene, and arylene moieties. Thesemoieties also include alkyl, alkenyl, alkynyl, and aryl moietiessubstituted with other aliphatic or cyclic hydrocarbon groups, such asalkaryl, alkenaryl and alkynaryl. Unless otherwise indicated, thesemoieties preferably comprise 1 to 30 carbon atoms.

The term “substituted hydrocarbyl” as used herein describes hydrocarbylmoieties that are substituted with at least one atom other than carbon,including moieties in which a carbon chain atom is substituted with ahetero atom such as nitrogen, oxygen, silicon, phosphorous, boron,sulfur, or a halogen atom. These substituents include halogen,heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protectedhydroxy, ketal, acyl, acyloxy, nitro, amino, amido, cyano, thiol,acetal, sulfoxide, ester, thioester, ether, thioether, hydroxyalkyl,urea, guanidine, amidine, phosphate, amine oxide, and quaternaryammonium salt.

The “substituted hydrocarbylene” moieties described herein arehydrocarbylene moieties which are substituted with at least one atomother than carbon, including moieties in which a carbon chain atom issubstituted with a hetero atom such as nitrogen, oxygen, silicon,phosphorous, boron, sulfur, or a halogen atom. These substituentsinclude halogen, heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy,hydroxy, protected hydroxy, ketal, acyl, acyloxy, nitro, amino, amido,cyano, thiol, acetal, sulfoxide, ester, thioester, ether, thioether,hydroxyalkyl, urea, guanidine, amidine, phosphate, amine oxide, andquaternary ammonium salt.

Unless otherwise indicated, the alkyl groups described herein arepreferably lower alkyl containing from one to 18 carbon atoms in theprincipal chain and up to 30 carbon atoms. They may be straight orbranched chain or cyclic and include methyl, ethyl, propyl, isopropyl,n-butyl, isobutyl, hexyl, 2-ethylhexyl, and the like.

Unless otherwise indicated, the alkenyl groups described herein arepreferably lower alkenyl containing from two to 18 carbon atoms in theprincipal chain and up to 30 carbon atoms. They may be straight orbranched chain or cyclic and include ethenyl, propenyl, isopropenyl,butenyl, isobutenyl, hexenyl, and the like. Unless otherwise indicated,the alkynyl groups described herein are preferably lower alkynylcontaining from two to 18 carbon atoms in the principal chain and up to30 carbon atoms. They may be straight or branched chain and includeethynyl, propynyl, butynyl, isobutynyl, hexynyl, and the like. The term“aryl” as used herein alone or as part of another group denoteoptionally substituted homocyclic aromatic groups, preferably monocyclicor bicyclic groups containing from 6 to 12 carbons in the ring portion,such as phenyl, biphenyl, naphthyl, substituted phenyl, substitutedbiphenyl or substituted naphthyl. Phenyl and substituted phenyl are themore preferred aryl.

The term “aralkyl” as used herein denotes a group containing both alkyland aryl structures such as benzyl.

As used herein, the alkyl, alkenyl, alkynyl, aryl and aralkyl groups canbe substituted with at least one atom other than carbon, includingmoieties in which a carbon chain atom is substituted with a hetero atomsuch as nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or ahalogen atom. These substituents include hydroxy, nitro, amino, amido,nitro, cyano, sulfoxide, thiol, thioester, thioether, ester and ether,or any other substituent which can increase the compatibility of thesurfactant and/or its efficacy enhancement in the potassium glyphosateformulation without adversely affecting the storage stability of theformulation.

The terms “halogen” or “halo” as used herein alone or as part of anothergroup refer to chlorine, bromine, fluorine, and iodine. Fluorinesubstituents are often preferred in surfactant compounds.

Unless otherwise indicated, the term “hydroxyalkyl” includes alkylgroups substituted with at least one hydroxy group, e.g.,bis(hydroxyalkyl)alkyl, tris(hydroxyalkyl)alkyl andpoly(hydroxyalkyl)alkyl groups. Preferred hydroxyalkyl groups includehydroxymethyl (—CH₂OH), and hydroxyethyl (—C₂H₄OH), bis(hydroxy-methyl)methyl (—CH(CH₂OH)₂), and tris (hydroxymethyl)methyl(—C(CH₂OH)₃).

The term “cyclic” as used herein alone or as part of another groupdenotes a group having at least one closed ring, and includes alicyclic,aromatic (arene) and heterocyclic groups.

The terms “heterocyclo” or “heterocyclic” as used herein alone or aspart of another group denote optionally substituted, fully saturated orunsaturated, monocyclic or bicyclic, aromatic or nonaromatic groupshaving at least one heteroatom in at least one ring, and preferably 5 or6 atoms in each ring. The heterocyclo group preferably has 1 or 2 oxygenatoms, 1 or 2 sulfur atoms, and/or 1 to 4 nitrogen atoms in the ring,and may be bonded to the remainder of the molecule through a carbon orheteroatom. Exemplary heterocyclo include heteroaromatics such as furyl,thienyl, pyridyl, oxazolyl, pyrrolyl, indolyl, quinolinyl, orisoquinolinyl and the like, and non-aromatic heterocyclics such astetrahydrofuryl, tetrahydrothienyl, piperidinyl, pyrrolidino, etc.Exemplary substituents include one or more of the following groups:hydrocarbyl, substituted hydrocarbyl, keto, hydroxy, protected hydroxy,acyl, acyloxy, alkoxy, alkenoxy, alkynoxy, aryloxy, halogen, amido,amino, nitro, cyano, thiol, thioester, thioether, ketal, acetal, esterand ether.

The term “heteroaromatic” as used herein alone or as part of anothergroup denote optionally substituted aromatic groups having at least oneheteroatom in at least one ring, and preferably 5 or 6 atoms in eachring. The heteroaromatic group preferably has 1 or 2 oxygen atoms, 1 or2 sulfur atoms, and/or 1 to 4 nitrogen atoms in the ring, and may bebonded to the remainder of the molecule through a carbon or heteroatom.Exemplary heteroaromatics include furyl, thienyl, pyridyl, oxazolyl,pyrrolyl, indolyl, quinolinyl, or isoquinolinyl and the like. Exemplarysubstituents include one or more of the following groups: hydrocarbyl,substituted hydrocarbyl, keto, hydroxy, protected hydroxy, acyl,acyloxy, alkoxy, alkenoxy, alkynoxy, aryloxy, halogen, amido, amino,nitro, cyano, thiol, thioether, thioester, ketal, acetal, ester andether.

The term “acyl,” as used herein alone or as part of another group,denotes the moiety formed by removal of the hydroxyl group from thegroup —COOH of an organic carboxylic acid, e.g., RC(O)—, wherein R isR¹, R¹O—, R¹R²N—, or R¹S—, R¹ is hydrocarbyl, heterosubstitutedhydrocarbyl, or heterocyclo and R² is hydrogen, hydrocarbyl orsubstituted hydrocarbyl.

The term “acyloxy,” as used herein alone or as part of another group,denotes an acyl group as described above bonded through an oxygenlinkage (—O—), e.g., RC(O)O— wherein R is as defined in connection withthe term “acyl.”

When a maximum or minimum “average number” is recited herein withreference to a structural feature such as oxyethylene units, it will beunderstood by those skilled in the art that the integer number of suchunits in individual molecules in a surfactant preparation typicallyvaries over a range that can include integer numbers greater than themaximum or smaller than the minimum “average number”. The presence in acomposition of individual surfactant molecules having an integer numberof such units outside the stated range in “average number” does notremove the composition from the scope of the present invention, so longas the “average number” is within the stated range and otherrequirements are met.

Herbicidal effectiveness is one of the biological effects that can beenhanced through this invention. AHerbicidal effectiveness, @ as usedherein, refers to any observable measure of control of plant growth,which can include one or more of the actions of (1) killing, (2)inhibiting growth, reproduction or proliferation, and (3) removing,destroying, or otherwise diminishing the occurrence and activity ofplants.

Having described the invention in detail, it will be apparent thatmodifications and variations are possible without departing from thescope of the invention defined in the appended claims.

EXAMPLES

The following non-limiting examples are provided to further illustratethe present invention.

Experimental Methods

The following describes the method of preparing the formulations andexperimental methods used to test the formulations in Examples 1 through4.

Formulation Preparation

In the following examples, glyphosate formulations were preparedcontaining water, glyphosate salt, and surfactant (either singlesurfactants or surfactant blends) according to the following order ofaddition:

-   -   (1) appropriate amount (g) of DI Water    -   (2) appropriate amount (g) of glyphosate salt solution    -   (3) appropriate amount (g) of amidoalkylamine surfactant    -   (4) appropriate amount (g) of co-surfactant/co-surfactant blend.

The components were added to 4 or 8 oz (118 mL or 236 mL) glass jars,and the formulations were stirred using magnetic stir bars at roomtemperature until clear. If the formulation did not clear after 24 hoursof mixing, it was described as unstable.

Formulations that were stable at room temperature for at least 2 hourswere held at −10° C. and 60° C. for four weeks for storage stabilitytesting. Changes in color, crystallization, and phase separation wereevaluated by a visual rating each week after the test began.

Formulations were tested for cloud point using the following procedure.Test formulation is poured into a 25 mm×200 mm Pyrex test tube to alevel of approximately 2 inches from the bottom. The test sample isheated until cloudy using a hot water bath. Temperature is monitoredusing an alcohol thermometer. Once the previously clear formulationbecomes cloudy, or the temperature reaches 80° C., the test sample isremoved from the water bath. If the formulation is clear throughout thetest, the cloud point is recorded as >80° C. If cloudy, the formulationis stirred with the alcohol thermometer until clear. The temperature atwhich the test sample clears is recorded as the formulation cloud point.

Efficacy Testing

The herbicidal effectiveness data set forth herein report “control” as apercentage following a standard procedure in the art which reflects avisual assessment of plant mortality and growth reduction by comparisonwith untreated plants, made by technicians specially trained to make andrecord such observations. In all cases, a single technician makes allassessments of percent control within any one experiment or trial. Suchmeasurements are relied upon and regularly reported by Monsanto Companyin the course of its herbicide business.

The following procedure was used for testing compositions of theExamples to determine herbicidal effectiveness, except where otherwiseindicated.

Seeds of the plant species indicated were planted in 85 mm square potsin a soil mix which was previously steam sterilized and prefertilizedwith a 14-14-14 NPK slow release fertilizer at a rate of 3.6 kg/m³. Thepots were placed in a greenhouse with sub-irrigation. About one weekafter emergence, seedlings were thinned as needed, including removal ofany unhealthy or abnormal plants, to create a uniform series of testpots.

The plants were maintained for the duration of the test in thegreenhouse where they received a minimum of 14 hours of light per day.If natural light was insufficient to achieve the daily requirement,artificial light with an intensity of approximately 475 microeinsteinswas used to make up the difference. Exposure temperatures were notprecisely controlled but averaged about 27° C. during the day and about21° C. during the night. Plants were sub-irrigated throughout the testto ensure adequate soil moisture levels.

Application of glyphosate compositions was made by spraying with a tracksprayer fitted with a 9501E nozzle calibrated to deliver a spray volumeof 93 liters per hectare (1/ha) at a pressure of 166 kilopascals (kPa).After treatment, pots were returned to the greenhouse until ready forevaluation.

Treatments were made using dilute aqueous compositions. These could beprepared as spray compositions directly from their ingredients, or bydilution with water of preformulated concentrate compositions.

For evaluation of herbicidal effectiveness, all plants in the test wereexamined by a single practiced technician, who recorded percent control,a visual measurement of the effectiveness of each treatment bycomparison with untreated plants. Control of 0% indicates no effect, andcontrol of 100% indicates that all of the plants are completely dead.Control of 85% or more is in most cases considered acceptable for normalherbicide use; however in greenhouse tests such as those for theExamples it is normal to apply compositions at rates which give lessthan 85% control, as this makes it easier to discriminate amongcompositions having different levels of effectiveness.

Example 1. Formulation Viscosity

The viscosities of various diammonium glyphosate salt formulations weredetermined as a function of surfactant type and surfactantconcentration. Viscosity with respect to temperature was measured usingTA Instruments, A R 2000 Rheometer. Five glyphosate formulationscontaining various loadings of C₈₋₁₀ amidopropyl dimethylamine, AdseeC80W (cocoamidopropyl dimethylamine), and a blend of surfactants(Ethoquad C/12 and an alkoxylated fatty alcohol) available in acommercial glyphosate formulation (labeled “blend” in Table 1 andFIG. 1) were studied using a step-flow procedure where temperature wasramped up from 0° C. to 10° C. and then to 20° C. Comparisons were madeat the 20° C. measurement. No viscosity increase was observed in any 360g a.e./L or 369 g a.e./L formulation regardless of surfactant type.Higher loading glyphosate formulations (480 g a.e./L) were also preparedhaving the components shown in Table 1:

TABLE 1 Glyphosate Surfactant Glyphosate concentration concentrationsalt (g a.e./L) Surfactant (g/L) 2 (NH₄) 480 Blend  83 2 (NH₄) 480 C₈₋₁₀amidopropyl  58 dimethylamine 2 (NH₄) 480 C₈₋₁₀ amidopropyl 120dimethylamine 2 (NH₄) 480 Adsee C80W  58 2 (NH₄) 480 Adsee C80W  66

FIG. 1 is a graph depicting the viscosities of the various diammoniumglyphosate salt formulations as a function of surfactant type andsurfactant loading.

The high load glyphosate formulations containing Adsee C80W werecharacterized by noticeably higher viscosity than the otherformulations. To lower the viscosity of the high load formulation, thetotal surfactant level was lowered to 58 g/L, such that the glyphosateto surfactant ratio was 8.3:1. It is believed that the high viscosity ofthe Adsee formulations resulted from the relatively basic pH of theformulation. Lowering the viscosity of the high glyphosate loadformulations employing Adsee C80W was accomplished in another manner bylowering the composition pH.

Formulations containing the C₈₋₁₀ amidopropyl dimethylamine surfactant(C8,10 APA in FIG. 1) were characterized by relatively low viscosityeven at a glyphosate to surfactant ratio of 4:1 even at alkaline pH. Itwas discovered that low viscosities were achieved over a broad pH rangefor high glyphosate load formulations employing the C₈₋₁₀ amidopropyldimethylamine surfactant.

Example 2. Greenhouse Bioefficacy Data of Glyphosate FormulationsContaining Adsee C80W

Glyphosate formulations containing Adsee C80W were prepared and testedfor bioefficacy. The bioefficacy of the formulations containing AdseeC80W were compared to RoundUp® Original and two formulations containingblends of Ethoquad surfactants (available from Akzo Nobel). Bioefficacyevaluations were done on common purslane (POROL) at application rates of280 g a.e., 560 g a.e., and 841 g a.e. per hectare of glyphosate,respectively, as shown from left to right for each formulation in FIG.2.

In each formulation, the source of glyphosate was diammonium glyphosatesalt. In two formulations, ethoxylated quaternary amines were blendedwith Adsee C80W to improve bioefficacy. In another formulation, AdseeC80W was coupled with the alkypolyglucoside surfactant2-ethyl-1-hexylglycoside (Akzo Nobel). In still another formulation,Adsee C80W was used as the only surfactant. The compositions of eachformulation are outlined in Table 2. In Table 2, 2E1H-glycoside refersto 2-ethyl-1-hexylglycoside, CIS refers to cationic surfactant and NISrefers to nonionic surfactant. Greenhouse data is summarized in FIG. 2wherein the first column for each formulation represents % POROL controlat an application rate of 280 g a.e./ha glyphosate, the second columnfor each formulation represents % POROL control at an application rateof 560 g a.e./ha glyphosate and the third column for each formulationrepresents % POROL control at an application rate of 841 g a.e./haglyphosate.

The glyphosate formulations 693A, 693D, 693E, and 917A described inTable 2 are diammonium glyphosate salt formulations containing AdseeC80W alone and blended with a co-surfactant. Also included in this studywere two formulations, 920B and 920D, containing blends of Ethoquad T/18and Ethoquad C/12. All glyphosate formulations were compared tocommercial standard Roundup® Original (as sold in Brazil). All samplescontaining Adsee C80W were significantly less efficacious than Roundup®Original. The samples containing Adsee C80W were the least efficacioussamples in this study. Comparison of formulations 693A and 693E, whichcontain Adsee C80W formulated with ethoxylated quaternary amines, toformulation 917A which contains Adsee C80W alone, indicates that theethoxylated quaternary amines do not provide improved bioefficacy onPOROL when formulated with Adsee C80W.

TABLE 2 Diammonium Glyphosate Formulations Containing Adsee C80W ActiveActive Amount of Amount of amount, % a.e. amount, surfactant surfactantForm. by mass g a.e./L Surfactant 1 1 (%) Surfactant 2 2 (%) 693A 38.4480 Adsee C80W 5.39 Ethoquad C/12 2.31 693D 38.4 480 Adsee C80W 5.392E1H- 2.31 glycoside 693E 38.4 480 Adsee C80W 5.39 Ethoquad C/15 2.31917A 30.2 360 Adsee C80W 7.63 — — 920B 30.2 360 Ethoquad T/18 5.18Ethoquad C/12 1.23 920D 30.2 360 Ethoquad T/18 4.95 Ethoquad C/12 0.95

Example 3. Greenhouse Bioefficacy Data of Glyphosate FormulationsContaining C₈₋₁₀ Amidopropyl Dimethylamine

High load glyphosate formulations containing C₈₋₁₀ amidopropyldimethylamine surfactant were prepared and tested for bioefficacy. Theefficacies of formulations containing C₈₋₁₀ amidopropyl dimethylaminesurfactant were compared against commercially available glyphosateformulations, two standard formulations, and two additional testformulations containing blends of quaternary amine surfactants. In eachformulation, the source of glyphosate was diammonium glyphosate salt.

Formulation details are summarized in Table 3. Formulations 163A, 163B,and 163C contained a blend of C₈₋₁₀ amidopropyl dimethylamine (“C₈₋₁₀APA” in Table 3) and a blend of quaternary tallowamine ethoxylate(Ethoquad T/20) and quaternary cocoamine (Ethoquad C/12) in a weightratio of 70:30. This is designated “blend” in Table 3. The ratio ofC₈₋₁₀ amidopropyl dimethylamine and blend were varied in each offormulations 163A, 163B, and 163C.

The commercial product Fosato® (a commercial product marketed byMonsanto in Argentina) was also tested for bioefficacy. Fosato® containsdiammonium glyphosate and surfactant in a ratio of g a.e./L glyphosateto g/L surfactant of 8.3:1. The formulations were also compared toStandard 1 (comprising 480 g a.e./L diammonium glyphosate with nosurfactant) and Standard 2 (containing 480 g a.e./L diammoniumglyphosate and a blend of ethoxylated quaternary amine and alkoxylatedfatty alcohol. The glyphosate a.e. to surfactant ratio in theformulations tested was maintained at 8:1, approximately equal toFosato®. Two additional formulations, 163D and 163E were included toinvestigate differences between Ethoquad C12 and C₈₋₁₀ amidopropyldimethylamine.

Evaluations were done on POROL at application rates of 426 g a.e., 628 ga.e., 841 g a.e., and 1120 g a.e. per hectare of glyphosate. TheGreenhouse data are summarized in FIG. 3 wherein the first column foreach formulation represents % POROL control at an application rate of426 g a.e./ha glyphosate, the second column for each formulationrepresents % POROL control at an application rate of 628 g a.e./haglyphosate, the third column for each formulation represents % POROLcontrol at an application rate of 841 g a.e./ha glyphosate and thefourth column for each formulation represents % POROL control at anapplication rate of 1120 g a.e./ha glyphosate.

Based on the greenhouse study, the bioefficacy of the glyphosateformulations containing C₈₋₁₀ amidopropyl dimethylamine werestatistically equal to Fosato® when applied to POROL. No statisticaldifferences were seen when comparing the formulations containing C₈₋₁₀amidopropyl dimethylamine to those containing Ethoquad C12. Standard 2was the most efficacious formulation tested. Additional studies werefocused on formulations containing higher surfactant loadings and testedagainst more efficacious formulations.

TABLE 3 Diammonium Glyphosate Formulations Containing C₈₋₁₀ AmidopropylDimethylamine Active Active Glyphosate amount, amount, Amount of Amountof a.e.: % a.e. g surfactant Surfactant surfactant Surfactant by massa.e./L Surfactant 1 1 (%) 2 2 (%) a.i. Fosato® 30.7 369 Ethoxylated NDAlkoxylated ND 8.3:1 quaternary fatty amine alcohol Standard 1 42.1 — —— — — Standard 2 40.1 480 Ethoxylated ND Alkoxylated ND 7.5:1 quaternaryfatty amine alcohol 163A 38.4 480 C₈₋₁₀ APA 2.88 Blend 1.92   8:1 163B38.4 480 C₈₋₁₀ APA 2.40 Blend 2.40   8:1 163C 38.4 480 C₈₋₁₀ APA 1.92Blend 2.88   8:1 163D 38.4 480 Ethoquad C/12 2.16 Blend 1.92   8:1 163E38.4 480 Ethoquad C/12 1.80 Blend 2.40   8:1 ND = not disclosed

Example 4. Greenhouse Bioefficacy Data of Glyphosate FormulationsContaining C₈₋₁₀ Amidopropyl Dimethylamine

Additional formulations were prepared containing glyphosate tosurfactant ratios up to 4:1 ae:ai and tested for bioefficacy.Evaluations were done on POROL at application rates of 426 g a.e., 628 ga.e., 841 g a.e., and 1120 g a.e. per hectare of glyphosate.

Diammonium glyphosate formulations (480 g a.e./L loadings) containingC₈₋₁₀ amidopropyl dimethylamine (“C₈₋₁₀ APA” in Table 4) blended withethoxylated quaternary tallowamine surfactants designated 199A and 753Awere prepared at pH 6.5. Diammonium glyphosate is typically formulatedas the dibasic salt and as such contains approximately two mols of NH₄per mol of glyphosate acid.

Formulations 199A and 753A were tested against commercially availableRoundup® Transorb® (480 g a.e./L loadings of the potassium glyphosatesalt in a ratio of glyphosate in g a.e./L to surfactant in g/L of 4:1)and a surfactant diluted version of Roundup® Transorb® (480 g a.e./Lloadings of the potassium glyphosate salt in a ratio of glyphosate in ga.e./L to surfactant in g/L of 5:1) designated “Transorb® dilute” inTable 4.

Higher load potassium glyphosate formulations (540 g a.e./L) containingC₈₋₁₀ amidopropyl dimethylamine (“C₈₋₁₀ APA” in Table 4) blended withethoxylated tertiary tallowamine surfactants designated 201B, 201C, and201D were prepared at pH 4.5. Potassium glyphosate is typicallyformulated as the monobasic salt and as such contains 1 mol K per mol ofGlyphosate acid.

Formulations 201B, 201C, and 201D were compared against a commercialproduct (designated “CS1” in Table 4 and in FIG. 4) containing 540 ga.e./l of glyphosate potassium salt, the formulation of which isdescribed in U.S. Pat. No. 6,365,551.

Measurement of pH can be according to any suitable protocol. Forexample, a sample of a test formulation of known weight is diluted indemineralized water to make a total solution mass of, say 100 g, whichis agitated, e.g., with a magnetic stir bar. A pH meter capable ofmeasuring pH to two decimal places, and fitted with an electrode withtemperature compensation, is calibrated with standard buffers, forexample pH 4.0 and pH 7.0. The solution pH is recorded when a stablereading is obtained. Between sample measurements the electrode should bewashed with and stored in demineralized water.

Greenhouse data are summarized in FIG. 4 wherein the first column foreach formulation represents % POROL control at an application rate of426 g a.e./ha glyphosate, the second column for each formulationrepresents % POROL control at an application rate of 628 g a.e./haglyphosate, the third column for each formulation represents % POROLcontrol at an application rate of 841 g a.e./ha glyphosate and thefourth column for each formulation represents % POROL control at anapplication rate of 1120 g a.e./ha glyphosate.

TABLE 4 Glyphosate Formulations Containing C₈₋₁₀ AmidopropylDimethylamine Amount Amount Active Active Total of of of pH (5 amount,amount All surfac- surfac- wt. % % a.e. g Salt Surfactant Surfactanttant 1 Surfactant tant 2 dilu- by mass a.e./L Type Comps (%) 1 (%) 2 (%)tion) Transorb® 36.3 480 K ND ND ND — — 4.5 Transorb® 36.3 480 K ND NDND — — 4.5 dilute 199A 38.4 480 2 (NH₄) 9.60 C₈₋₁₀ APA 4.80 Ethoquad4.80 6.5 T/18Q 753A 38.4 480 2 (NH₄) 9.60 C₈₋₁₀ APA 4.80 Ethoquad 4.806.5 T/20Q CS1 540 K ND ND ND ND ND ND 201B 39.8 540 K 10.00 C₈₋₁₀ APA4.00 Ethomeen 6.00 4.5 T/20 201C 39.8 540 K 10.00 C₈₋₁₀ APA 5.00Ethomeen 5.00 4.5 T/20 201D 39.8 540 K 10.00 C₈₋₁₀ APA 6.00 Ethomeen4.00 4.5 T/20 ND = not disclosed

Formulations 199A and 753A are diammonium glyphosate formulations (480 ga.e./L) containing blends of C₈₋₁₀ amidopropyl dimethylamine andethoxylated quaternary tallowamine surfactants. Formulations 201B, 201C,and 201D are potassium glyphosate formulations (540 g a.e./L) thatcontain blends of C₈₋₁₀ amidopropyl dimethylamine and ethoxylatedtertiary tallowamine surfactants. Because of the improved formulationstability offered by the C₈₋₁₀ amidopropyl dimethylamine, C₈₋₁₀amidopropyl dimethylamine may be used in place of cocoamine 2 EOsurfactants known in the art. Moreover, the level of ethoxylatedtallowamine in the experimental formulations has been increased up to60% of the total surfactant blend, which exceeds the content of currentcommercial standards. Replacement of cocoamine 2 EO surfactants withC₈₋₁₀ APA allows levels of tallowamine to be increased which improvesformulation bioefficacy. Replacement of cocoamine 2 EO with C₈₋₁₀ APAhas also been discovered to improve formulation compatibility withtank-mixed co-herbicides and reduce the level of eye irritation.

The bioefficacy improvement in the experimental formulations 201B, 201C,and 201D over the commercial product (“CS1”) is illustrated by the datashown in FIG. 4. This improvement is especially evident at the low andhigh rates. Formulations 199A and 753A were statistically lessefficacious than Roundup® Transorb® (4:1 glyphosate to surfactantratio), but equal to Roundup® Transorb® dilute (5:1 glyphosate tosurfactant ratio). The data suggest that combinations of C₈₋₁₀amidopropyl dimethylamine and ethoxylated quaternary surfactants areless efficacious than combinations of C₈₋₁₀ amidopropyl dimethylamineand ethoxylated tertiary amine surfactants. The reason for thisreduction in performance at more neutral pH is believed to be related tothe less cationic nature of the amidopropyl dimethylamine surfactant atthat pH.

Example 5. Formulation Stability Testing: Cloud Point Data

Cloud point is a parameter both for measuring storage stability and forevaluating compatibility of surfactants in high load potassiumglyphosate salt formulations. Cloud point measurement methods are knownin the art. The cloud point of a formulation is normally determined byheating the formulation until the solution becomes cloudy, and thenallowing the formulation to cool, with agitation, while its temperatureis continuously monitored. A temperature reading taken when the solutionclears is a measure of cloud point. A cloud point of 50° C. or more isnormally considered acceptable for most commercial purposes for aglyphosate concentrate formulation.

Potassium glyphosate and diammonium glyphosate formulations wereprepared and subjected to cloud point testing. The formulationcomposition and resulting cloud points are reported in Table 5 whereinT20 refers to a tertiary tallow amine ethoxylate having 10EO (EthomeenT/20), C12Q refers to a quaternary cocoamine amine ethoxylate having 2EO(Ethoquad C/12), C₈₋₁₀ APA refers to C₈₋₁₀ amidopropyl dimethylamine,T18 refers to a tertiary tallow amine ethoxylate having 8EO (EthomeenT/18), T20Q refers to a quaternary tallowamine amine ethoxylate having10EO (Ethoquad T/20) and C12 refers to a tertiary coco amine ethoxylatehaving 2EO (Ethomeen C/12). In further reference to Table 5, the ratioof the surfactant is reported in parentheses. The potassium glyphosatesalt formulations contained either 480 g a.e./L and 540 g a.e./L andwere formulated with the objective of determining whether C₈₋₁₀amidopropyl dimethylamine surfactant is a suitable replacement forcocoamine 2EO surfactants. The diammonium glyphosate formulationscontained 480 g a.e./L and were formulated with the objective ofdetermining whether C₈₋₁₀ amidopropyl dimethylamine surfactant is asuitable replacement for quaternary cocoamine 2EO surfactant.

Cloud point testing revealed that diammonium glyphosate formulations(480 g a.e./L) could be prepared with up to 120 g/L of C₈₋₁₀ amidopropyldimethylamine and quaternary tallowamine surfactant blends containing upto 8 to 10 moles of ethoxylation on the quaternary tallowamine. TheC₈₋₁₀ amidopropyl dimethylamine was shown to be a good compatibilityagent for potassium glyphosate salt formulations containing 540 g a.e./Lloading. A potassium glyphosate salt formulation (540 g a.e./L)containing 135 g/L surfactant at a 60/40 ratio of Ethomeen T20/APA wasprepared with a cloud point over 65° C. This suggests that replacementof the cocoamine component of a potassium glyphosate formulation withC₈₋₁₀ amidopropyl dimethylamine could allow higher levels of tallowamineethoxylate and reduced levels of coupling agent. The formulationsprepared and the cloud point data associated with them are summarized inTable 5.

Each formulation prepared with cocoamine or quaternary cocoamine has acorresponding formulation prepared with C₈₋₁₀ amidopropyl dimethylamine.In all cases, a significant cloud point improvement was noted in samplescontaining C₈₋₁₀ amidopropyl dimethylamine surfactants versus cocoamineor quaternary cocoamine surfactants. These results suggest that C₈₋₁₀amidopropyl dimethylamine surfactants are more efficient coupling agentsthan the cocoamine or quaternary cocoamine 2EO for ethoxylatedquaternary amine and ethoxylated tertiary amine surfactants informulations containing diammonium glyphosate salt and potassiumglyphosate salt.

TABLE 5 Cloud points for Various formulations containing C₈₋₁₀Amidopropyl Dimethylamine and Tertiary Amine or Quaternary AmineCoupling Agents Glyphosate Blend Salt Loading (g Loading Specific CloudPoint Sample ID type a.e./L) Blend Type (g/L) Gravity (° C) 203A 2 (NH₄)370 T20/C12Q (60/40) 45 1.197 less than 40 203B 2 (NH₄) 370 T20/C₈₋₁₀APA (60/40) 45 1.197 >80  203C 2 (NH₄) 360 T18/C12Q (70/30) 60 1.194 43203D 2 (NH₄) 360 T18/C₈₋₁₀ APA (70/30) 60 1.193 67 203E 2 (NH₄) 360T18/C12Q (70/30) 72 1.194 less than 40 203F 2 (NH₄) 360 T18/C₈₋₁₀ APA(70/30) 72 1.193 64 203G 2 (NH₄) 360 T18/C12Q (55/45) 90 1.194 63 203H 2(NH₄) 360 T18/C₈₋₁₀ APA (55/45) 90 1.191 >80  203I 2 (NH₄) 480 T20Q/C12Q(50/50) 120 unstable unstable 203J 2 (NH₄) 480 T20Q/C₈₋₁₀ APA (40/60)120 1.250 less than 60 203K 2 (NH₄) 480 T20Q/C12Q (50/50) 96 unstableunstable 203L 2 (NH₄) 480 T20Q/C₈₋₁₀ APA (40/60) 96 1.250 >80  203M 2(NH₄) 480 T20Q/C12Q (50/50) 80 unstable unstable 203N 2 (NH₄) 480T20Q/C₈₋₁₀ APA (50/50) 80 1.244 >80  203O 2 (NH₄) 480 T20Q/C12Q (50/50)60 unstable unstable 203P 2 (NH₄) 480 T20Q/C₈₋₁₀ APA (50/50) 601.247 >80  202A K 540 120/C12 (60/40) 135 1.365 less than 40 202B K 540T20/C₈₋₁₀ APA (60/40) 135 1.365 68 202C K 480 T20/C12 (80/20) 120unstable unstable 202D K 480 T20/C₈₋₁₀ APA (80/20) 120 unstable unstable202E K 480 T20/C12 (70/30) 120 1.329 46 202F K 480 T20/C₈₋₁₀ APA (70/30)120 1.329 >80 

Example 6. Formulation Stability Testing at −10° C. and 60° C.

The potassium glyphosate and diammonium glyphosate formulations fromExample 5 were subjected to storage stability testing at cold and hottemperatures. Table 6 summarizes the storage stability results of thoseformulations at both 60° C. and −10° C.

Seven of the formulations prepared remained clear and stable after 4weeks of storage at 60° C. and −10° C. All seven of those formulationscontained C₈₋₁₀ amidopropyl dimethylamine surfactant. This Exampleillustrates the compatibility improvement provided by the C₈₋₁₀amidopropyl dimethylamine surfactant of the present invention ascompared to the prior art ethoxylated cocoamine and quaternary cocoaminesurfactants.

The stability of these formulations can be affected by adjusting theratio of C₈₋₁₀ amidopropyl dimethylamine to ethoxylated amine orquaternary amine. Reformulating unstable formulations 203F, 203J and203L with increased levels of the C₈₋₁₀ amidopropyl dimethylamineresulted in improved stability. The reformulated samples are describedin Table 7 as 214A, 214B, 214C, 214D, and 214E. These formulations werestored for two weeks at −10° C. and 60° C. After 2 weeks, all werestable at −10° C. All formulations except 214B were stable at 60° C.

TABLE 6 Sample ID Stability (−10° C.) Stability (60° C.) 203A clear andstable unstable @ 1 week 203B clear and stable clear and stable 203Cclear and stable unstable @ 1 week 203D clear and stable clear andstable 203E clear and stable unstable @ 1 week 203F clear and stableunstable @ 1 week 203G clear and stable unstable @ 1 week 203H clear andstable clear and stable 203I unstable @ RT unstable @ RT 203J unstable @1 week unstable @ 1 week 203K unstable @ RT unstable @ RT 203L unstable@ 2 weeks unstable @ 2 weeks 203M unstable @ RT unstable @ RT 203N clearand stable clear and stable 203O unstable @ RT unstable @ RT 203P clearand stable clear and stable 202A clear and stable unstable @ 1 week 202Bclear and stable clear and stable 202C unstable @ RT unstable @ RT 202Dunstable @ RT unstable @ RT 202E clear and stable unstable @ 1 week 202Fclear and stable clear and stable

TABLE 7 Glyphosate Blend Sample Salt Loading (g Loading Specific CloudPoint Stability (2 ID type a.e./L) Blend Type (g/L) Gravity (° C) weeks)214A 2 (NH₄) 360 T18/C₈₋₁₀ APA 72 1.191 >80 stable (60/40) 214B 2 (NH₄)480 T20Q/C₈₋₁₀ APA 120 1.250 less than 60 unstable @ 60 (40/60) 214C 2(NH₄) 480 T20Q/C₈₋₁₀ APA 96 1.250 >80 stable (40/60) 214D 2 (NH₄) 480T18Q/C₈₋₁₀ APA 120 1.250 >80 stable (50/50) 214E 2 (NH₄) 480 T18Q/C₈₋₁₀APA 96 1.250 >80 stable (50/50)

The following conclusions may be made from the results of Examples 1through 6. Amidoalkylamine surfactants are efficient coupling agents forethoxylated tertiary amine and ethoxylated quaternary amine surfactantsin high load potassium glyphosate and diammonium glyphosateformulations, respectively. The hydrocarbyl chain of this class ofsurfactants plays an important role in the physical properties of theend formulation. Cocoamidopropyl amine surfactants (Adsee C80W)increased the viscosity of 480 g a.e./L diammonium formulations whenadded at concentrations greater than 58 g/L. The C₈₋₁₀ amidopropyldimethylamine surfactants had little effect on formulation viscosity.Formulations prepared with the C₈₋₁₀ amidopropyl dimethylaminesurfactants had acceptable viscosity even at a surfactant loading of 120g/L.

Greenhouse bioefficacy studies indicated that blends of amidoalkylaminesurfactants with ethoxylated tertiary amines and ethoxylated quaternaryamines are effective delivery systems for glyphosate. This may be due inpart to the improved formulation stability that allows for theformulation of higher levels of ethoxylated tertiary tallowaminesurfactants to be used in high load potassium glyphosate formulationsand higher levels of ethoxylated quaternary amine surfactants in highload diammonium glyphosate formulations. The data suggest improvedperformance of the amidoalkylamine surfactants when combined withethoxylated tertiary amine surfactants more so than ethoxylatedquaternary amine surfactants.

Formulation stability studies indicated that C₈₋₁₀ amidopropyldimethylamine surfactants are more efficient coupling agents thancocoamine and quaternary ethoxylated cocoamine (2 EO). For example, ahigh load potassium glyphosate formulation (540 g a.e./L) prepared with135 g/L surfactant required a 55/45 wt % blend of tallowamine 10 EO andcocoamine 2EO to have a cloud point of 60° C. This same formulationcould be prepared at a 60/40 wt % blend of tallowamine 10 EO and C₈₋₁₀amidopropyl dimethylamine. The increased levels of tallowamineethoxylate improve formulation bioefficacy. Accordingly, amidoalkylaminesurfactants offer new opportunities to develop high load glyphosateformulations, and amidoalkylamine surfactants are suitable substitutesfor 2 EO cocoamine surfactants.

Example 7. Compatibilization with Co-Herbicides

In some glyphosate formulations, it is advantageous to incorporate aco-herbicide into the spray tank to enhance bioefficacy, to induce earlyappearance of visual phytotoxic effects in treated plants, or both. Inthis regard, amidoalkylamine surfactants have been discovered to enhancethe stability of high load glyphosate formulations further comprising atank mixed co-herbicide.

High load potassium glyphosate formulations were prepared comprising thecomponents as shown in the following Table 8 wherein T20 is tertiarytallow amine ethoxylate having 10 moles of EO and APA is C₈₋₁₀amidopropyl dimethylamine.

TABLE 8 Glyphosate Blend Sample Salt Loading (g Loading ID type a.e./L)Blend Type (g/L) pH 922A K 540 T20/C₈₋₁₀ APA 135 4.5 (60/40) 922B K 540T20/C₈₋₁₀ APA 135 5.0 (55/45)

Eight glyphosate samples were prepared in hard water and furthercomprising a co-herbicide. Two samples (100 mL each) were prepared from922A, and two samples (100 mL each) were prepared from 922B. Twocomparative samples (100 mL each) were prepared from a commercialproduct (designated “CS1” in Tables 9A and 9B) containing 540 g a.e./Lof glyphosate potassium salt and described in U.S. Pat. No. 6,365,551,and two additional comparative samples (100 mL each) were prepared froma second commercial standard (designated “CS2” in Tables 9A and 9B)containing 540 g a.e./L of glyphosate potassium salt. Each of sample wasprepared according to the following protocol:

-   1) Fill a Nesslar tube with a pre-determined amount of 342 ppm    hardness water.-   2) Add ammonium sulfate if necessary; mix until dissolved.-   3) Add a co-herbicide. In one sample of each formulation,    (2,4-dichlorophenoxy)acetic acid (2,4-D) was added (total volume of    2.5 mL). In the other sample of each formulation, Direx (diuron) was    added (total volume of 4 mL).-   4) Add the glyphosate formulation.-   5) Invert Nesslar tube 10 times.-   6) Evaluate for precipitate immediately, at 1 hour, and at 2 hours.-   7) Let stand for 24 hours-   8) Evaluate for precipitation/haziness and determine number of    inversions necessary to re-disperse.

The observed results are shown in Tables 9A (samples comprising 2,4-Dco-herbicide) and 9B (samples comprising Direx).

TABLE 9A Time to Precipitate Sample ID Immediate Formation CS1 Clear 14minute CS2 Hazy 4.5 minutes 922A Hazy 14 minutes 922B Clear Clear after7 hours

TABLE 9B Sample ID Immediate After 2 hours CS1 Immediate Direx settlesto bottom Flocculation CS2 Immediate Direx settles to bottomFlocculation 922A Remains in Slight top clearing; Suspension solution insuspension 922B Remains in Slight top clearing; Suspension solution insuspension

Based on the above observations, it is apparent that the blend oftertiary tallow amine ethoxylate having 10 moles of EO and C₈₋₁₀amidopropyl dimethylamine enhances the compatibility of co-herbicideswithin high potassium glyphosate load herbicidal compositions, comparedto current commercial formulations.

Example 8. Eye Toxicity Improvement

In some glyphosate formulations it has been shown as advantageous to thebiological efficacy to incorporate a surfactant. Common surfactants usedin the art include tertiary amine ethoxylates. Glyphosate formulationscontaining tertiary amine ethoxylate surfactants are sometimes known tobe irritating to the eyes. Formulations prepared with a blend oftertiary amine ethoxylates and amidoalkylamine surfactants have beendiscovered to be less irritating to the eyes than formulationscontaining tertiary amine ethoxylates alone and even in some cases canmitigate the irritation caused by similar levels of ethoxylated tertiarytallowamine surfactants.

Two potassium glyphosate formulations (540 g a.e./L) comprising a blendof surfactants (135 g/L) were prepared. One glyphosate formulationcontained a blend of tertiary tallowamine ethoxylate having 10 moles EOand C₉-amidopropyl dimethylamine. The other formulation contained ablend of tertiary tallowamine ethoxylate having 10 moles EO and atertiary cocoamine ethoxylate having 2 mols EO.

Both formulations were tested for eye irritation using a standard eyeirritation screen. Each of three New Zealand White Rabbits received a0.1 mL dose of the test substance in the conjunctival sac of the righteye. The contralateral eye of each animal remained untreated and servedas a control. Test and control eyes were examined for signs ofirritation for up to 10 days.

The glyphosate formulation containing the blend of tertiary tallowamineethoxylate with 10 mols EO and tertiary cocoamine ethoxylate with 2moles EO, exposure to the test article produced corneal opacity in 1/3test eyes at the 1-hour scoring interval. The corneal opacity wasconfirmed by positive fluorescein dye retention at the 24-hour scoringinterval. The corneal opacity resolved in the test eye by the 72-hourscoring interval. Iritis was observed in 2/3 test eyes at the 1-hourscoring interval which resolved completely by the 48-hour scoringinterval. The conjunctival irritation resolved completely in all testeyes by study-day 10.

The glyphosate formulation containing the blend of tertiary tallowamineethoxylate with 10 moles EO and C₉-amidopropyl dimethylamine, exposureto the test article did not produce corneal opacity in any of the testeyes exposed. Iritis was observed in 3/3 test eyes at the 1-hour scoringinterval which resolved completely by the 48-hour scoring interval.Conjunctival irritation resolved completely in all test eyes by 72 hoursafter exposure.

Based on the above results, it is apparent that 540 g a.e./L potassiumglyphosate formulations containing a blend of tertiary tallowamineethoxylate having 10 moles EO and C₉-amidopropyl dimethylamine are lessirritating to the eyes than blends of tertiary amine ethoxylates. Thisis especially illustrated by the reduction in corneal effects in thatsample compared to the sample containing the tertiary cocoamineethoxylate.

Example 9. Amidoalkylamine Coupling Experiments

The ability of amidoalkylamine surfactants to compatibilize a widevariety of co-surfactants was tested in high load potassium glyphosateformulations. Glyphosate formulations were prepared containing potassiumglyphosate at a loading of 39.7 wt. % (about 540 g a.e./L). Everyformulation contained at least a primary surfactant (Surfactant A inTable 10), at 8.0 wt. % (about 108 g/L). The control formulationscontained only the primary Surfactant A. The test formulations containedthe same amount of primary Surfactant A and an additional amount ofC₉-amidopropyl dimethylamine coupling agent (C9 APA in Table 10) at 2.0wt. % (about 27 g/L), 3.0 wt. % (about 40.5 g/L), or 4 wt. % (about 54g/L). The observed stability at room temperature and cloud point dataare shown in Table 10.

TABLE 10 Wt. % Stability at Sample of C9 Room Cloud Point ID SurfactantA APA Temperature (° C.) 802A Alkoxylated Etheramine 0.0 Stable 67Ethoxylate 802B Alkoxylated Etheramine 2.0 Stable >80 Ethoxylate 802CTOMAH E-17-5 0.0 Unstable NA 802D TOMAH E-17-5 2.0 Stable 65 802E Oxideof etheramine 0.0 Unstable NA 802f Oxide of etheramine 2.0 Stable 68802G Phosphate ester of 0.0 Stable 40 alkyletheramine 802H Phosphateester of 2.0 Stable >80 alkyletheramine 802I TOMAH AO-17-7 0.0 UnstableNA 802J TOMAH AO-17-7 2.0 Unstable NA 802K TOMAH AO-17-7 3.0 Unstable NA802L TOMAH AO-17-7 4.0 Stable 54 802M AROMOX C/12 0.0 Unstable NA 802NAROMOX C/12 2.0 Stable NA

TOMAH E-17-5 is poly(5)oxyethylene isotridecyloxypropylamine having thestructure:

TOMAH AO-17-7 is poly(7)oxyethylene isotridecyloxypropylamine oxidehaving the structure:

AROMOX C/12 is bishydroxyethylcocoamine oxide having the structure:

The data of Table 10 show that amidoalkylamine surfactants enable thepreparation of stable high load glyphosate with a wide variety ofco-surfactants. In each experiment, the high load glyphosateformulations containing primary Surfactant A only were either unstableand thus incompatible with a high load glyphosate formulation or thestability of the formulation was improved by the addition of anamidoalkylamine coupling agent. In Table 10, a demarcation of “unstable”indicates that the glyphosate formulation was characterized by a twophase composition. While some surfactants yield stable compositions,those surfactants that yielded unstable compositions became stable withthe addition of C₉-amidopropyl dimethylamine. In each formulation test,except for those containing AROMOX C/12, addition of C₉-amidopropyldimethylamine increased the cloud point, further showing improvedformulation stability. With regard to AROMOX C/12, although a cloudpoint improvement was not observed, the addition of C₉-amidopropyldimethylamine caused the two-phase composition to stabilize into asingle phase.

Example 10. Herbicidal Compositions Comprising Blends of GlyphosateSalts

The cloud point stability of a variety of high load glyphosateformulations comprising a blend of glyphosate salts was studied. Eachformulation comprised a blend of potassium glyphosate andmonoethanolamine glyphosate at a glyphosate loading of 540 g a.e./L anda weight ratio of potassium glyphosate in g a.e. to monoethanolamineglyphosate in g a.e. of 70:30.

Samples 820D through 820F are test formulations that comprised a blendof potassium glyphosate and monoethanolamine glyphosate at a glyphosateloading of 540 g a.e./L and a weight ratio of potassium glyphosate in ga.e. to monoethanolamine glyphosate in g a.e. of 70:30 and furthercomprising Ethomeen T/20, available from Akzo Nobel and C₉-amidopropyldimethylamine coupling agent (C9 APA in Table 11). The surfactantloadings of samples 820D, 820E, and 820F were 130 g/L, 120 g/L, and 110g/L, respectively, and the weight ratio of Ethomeen T/20 in grams toC₉-amidopropyl dimethylamine coupling agent in grams was 65:35, 70:30,and 70:30, respectively.

For comparison, samples 820A through 820C are formulations thatcomprised a blend of potassium glyphosate and monoethanolamineglyphosate at a glyphosate loading of 540 g a.e./L and a weight ratio ofpotassium glyphosate in g a.e. to monoethanolamine glyphosate in g a.e.of 70:30 and further comprising a blend of Ethomeen T/20 and EthomeenC/12, both available from Akzo Nobel. The surfactant loadings of samples820A, 820B, and 820C were 130 g/L, 120 g/L, and 110 g/L, respectively,and the weight ratio of Ethomeen T/20 in grams to Ethomeen C/12 in gramswas 60:40, 65:35, and 65:35, respectively.

Samples 842A, 612H, and 612I are formulations that comprised a blend ofpotassium glyphosate and monoethanolamine glyphosate at a glyphosateloading of 540 g a.e./L and a weight ratio of potassium glyphosate in ga.e. to monoethanolamine glyphosate in g a.e. of 70:30 and furthercomprising a blend of Ethomeen T/20 and Ethomeen C/12, both availablefrom Akzo Nobel. The surfactant loadings of samples 842A, 612H, and 612Iwere 130 g/L, 120 g/L, and 110 g/L, respectively, and the weight ratioof Ethomeen T/20 in grams to Ethomeen C/12 in grams was 65:35, 70:30,and 70:30, respectively.

Samples 842B, 842C, and 842D are formulations that comprised a blend ofpotassium glyphosate and monoethanolamine glyphosate at a glyphosateloading of 540 g a.e./L and a weight ratio of potassium glyphosate in ga.e. to monoethanolamine glyphosate in g a.e. of 70:30 and furthercomprising a Ethomeen T/20 alone. The surfactant loadings of samples842A, 612H, and 612I were 130 g/L, 120 g/L, and 110 g/L, respectively.

Table 11 below illustrates the improved compatibility offered byamidoalkylamine surfactants in formulations comprising a blend ofglyphosate salts.

TABLE 11 Cloud Sample Surf Point ID Loading Surf Desc. (° C. SG pH 820D130 Ethomeen T20/C9 APA >80 1.338 4.65 820E 120 Ethomeen T20/C9 APA >801.341 4.63 820F 110 Ethomeen T20/C9 APA >80 1.341 4.6 820A 130 EthomeenT20/ 71 1.338 4.63 Ethomeen C12 820B 120 Ethomeen T20/ 67 1.341 4.61Ethomeen C12 820C 110 Ethomeen T20/ 71 1.341 4.59 Ethomeen C12 842A 130Ethomeen T20/ 59 1.338 4.65 Ethomeen C12 612H 120 Ethomeen T20/ 52 1.3414.61 Ethomeen C12 612I 110 Ethomeen T20/ 57 1.342 4.59 Ethomeen C12842B* 130 Ethomeen T20 unstable 1.388 4.6 842C* 120 Ethomeen T20unstable 1.341 4.6 842D* 110 Ethomeen T20 unstable 1.341 4.6 ND = notdisclosed *Specific Gravity and pH not measured. Values are estimatesbased on similar formulations. These samples were unstable at Room temp.

Formulations that contained a blend of Ethomeen T/20 and C₉-amidopropyldimethylamine coupling agent with elevated levels of tallowamineethoxylate showed cloud points of >80° C., which was more than 20° C.higher for the corresponding formulations made with a blend of EthomeenT/20 and Ethomeen C/12 formulations with the same level of tallowamine.In some instances, the relatively lower cloud point means that someformulations, such as 612H, may be prone to failure under commercialstorage conditions. The cloud point increase illustrates the stabilityimprovement offered by the amidoalkylamine surfactants compared tococoamine 2 EO in this mixed salt system. Furthermore, this exampleillustrates the feasibility of preparing highly loaded glyphosateformulations with blends of salts. More specifically this exampledetails the preparation of highly loaded glyphosate formulationscontaining amido alkylamine surfactants and at least one othersurfactant not by itself stable in that salt or blend of salts ofglyphosate.

Example 11. Herbicidal Compositions Comprising Blends of GlyphosateSalts and Compatibilization with Co-Herbicides

The cloud point stability of a variety of high load glyphosateformulations comprising a blend of glyphosate salts was studied. Theseformulations were additionally tested for their compatibility withco-herbicide (2,4-dichlorophenoxy)acetic acid (2,4-D). The results ofthese studies are shown below in Table 12. The glyphosate load in everysample was 480 g a.e./L, obtained by adding potassium glyphosate. Insome samples, aqueous ammonium was added such that these samplescomprised a blend of potassium and ammonium glyphosate salts.

In every sample, surfactant 1 was Ethomeen T/20, available from AkzoNobel. In those samples wherein surfactant 2 was added, surfactant 2 wasC₈₋₁₀-amidopropyl dimethylamine coupling agent.

To test the compatibility of each formulation with 2,4-D, the herbicidalconcentrate solution was added dropwise to a solution of 2,4-Ddimethylamine. The 2,4-D dimethylamine solution was stirred with amagnetic stirrer during dropwise addition. Dropwise addition continueduntil the solution became turbid. The 2,4-D dimethylamine was preparedby adding 7.7 g of 2,4D dimethylamine (46.9% 2,4-D) from Riverside/TerraCorp. to a beaker containing 86 g of deionized water. Upon becomingturbid, the beaker was weighed to determine the amount of formulationadded. That weight was recorded.

TABLE 12 29% NH₄ Wt. % of Wt. % of 2,4-D Sample by mass SurfactantSurfactant Cloud Compatibility ID (%) 1 2 Point (°) Test Result 718A 0 50 unstable n 718C 1.5 5 2 >90 7 718D 3 5 4 >90 6.3 718E 1.5 6 0 unstablen 718F 3 6 2 40 8.8 718G 0 6 4 >90 4.3 718H 3 8 0 unstable n 718I 0 8 2unstable n 718J 1.5 8 4 72 10.4 718K 0 5 1 61 6.4 718L 1.51 6 1 unstable3.6 718M 3.1 8 1 unstable n 718N 0 8 2 unstable 3.5 718O 1.5 7 2unstable 4.7 718P 1.5 6 2 47 4.8 718Q 3 6 3 35 15.3 718R 1.3 6 3 75 14.5718S 2 6.3 3 59 9.8 718T 1.5 7.1 3 43 7.2 729A 0 5 1 57 3 729B 2.5 6 2unstable n 729C 2.5 5 2 47 5.4 729D 2.5 5.5 1.5 unstable n 729E 2 5 2 624.3 729F 2 4 1 25 4.4 729G 3 4 2 68 3.8 730H 3 4 3 72 3.5 731I 2.5 53 >90 4.2 731J 3 5 3 >90 4.3 731K 3.5 5 3 >90 4.9 731L 4 5 2 68 4.4 731M4.5 4 3 >90 6 731N 5.5 4 3 >90 6 731O 6 4 3 >90 6.6 731P 7 4 3 >90 n731Q 10 4 3 68 6 731R 4.5 4.5 2.5 >90 5.2 731S 9 4 3 77 9.5 731T 10 4 362 7.8 N = not tested

The results of Table 12 indicate that the inclusion of C₈₋₁₀-amidopropyldimethylamine coupling agent increased the cloud point of theformulation.

Example 12. High Load Glyphosate Formulations

Several formulations were prepared comprising glyphosate loads greaterthan 560 g a.e./L of potassium glyphosate and tested by cloud pointstudies for stability. The results of these studies are shown below inTable 13. In each formulation, Surfactant 1 (“Surf. 1”) is EthomeenT/20, available from Akzo Nobel. Surfactant 2 (“Surf. 2”), where added,is Ethomeen C/12 available from Akzo Nobel. Surfactant 3 (“Surf. 3”) isC₉-amidopropyl dimethylamine coupling agent. In Table 13, Stabilitypertains to the appearance of a precipitate after the formulation washeld at 0° C. for 1 month.

TABLE 13 Active amount, Active Wt. % Wt. % Wt. % Cloud % ae by Amount gSurf. Surf. Surf. Point mass a.e./L 1 2 3 (° C) Stability 40.85 560 7 30  53 no crystals 40.85 560 4.9 2.1 3 >90 no crystals 40.85 560 3.5 1.55 >90 no crystals 40.85 560 2.1 0.9 7 >90 no crystals 40.85 560 6 0 4 64 no crystals 40.85 560 7 0 3 unstable no crystals 40.85 560 5.5 0 4.5 86 no crystals 41.45 572 6 0 4  50 no crystals 41.45 572 5.5 0 4.5  79no crystals

In view of the results shown in Table 13, it is apparent thatC₉-amidopropyl dimethylamine coupling agent is an effective couplingagent for stabilizing high glyphosate load formulations as shown by thecloud point study and long term stability at 0° C.

Example 13. Glyphosate Formulations Containing a Blend ofAmidoalkylamine Surfactants and Alkoxylated Alcohol Co-Surfactants

The ability of amidoalkylamine surfactants to compatibilize alkoxylatedalcohols and form stable formulations with these co-surfactants wastested in high load potassium glyphosate formulations. Glyphosateformulations were prepared containing potassium glyphosate at a loadingof 39.7 wt. % (about 540 g a.e./L). Every formulation contained at leastan alkoxylated alcohol surfactant. In Table 14, the identities of thealkoxylated alcohol surfactant are as follows: (1) Ethoxylated Alcohol Ais a C_(16,18) alcohol ethoxylated with an average of 20 moles EO, (2)Ethoxylated Alcohol B is a C_(16,18) alcohol ethoxylated with an averageof 15 moles EO, (3) Ethoxylated Alcohol C is a C_(12,16) alcoholethoxylated with an average of 22 moles EO, (4) Ethoxylated Alcohol D isa C_(12,16) alcohol ethoxylated with an average of 7 moles EO, and (5)Ethoxylated Alcohol E is a C_(10,12) alcohol ethoxylated with an averageof 8 moles EO. Control formulations contained only the alcoholsurfactant, while in test formulations, a C₉-amidopropylamine (“C9 APA”)coupling agent was added. The relative amounts of each surfactant werevaried as shown in Table 14. The formulations were observed forstability at room temperature, and the results are shown in Table 14.

TABLE 14 Wt. % Wt. Stability Sample Alkoxylated Alkoxylated % C9 at RoomID alcohol Alcohol APA Temperature 863A Ethoxylated 8.10 0.00 UnstableAlcohol A 863B Ethoxylated 4.05 4.05 Unstable Alcohol A 863C Ethoxylated2.03 6.08 Unstable Alcohol A 863D Ethoxylated 8.10 0.00 Unstable AlcoholB 863E Ethoxylated 4.05 4.05 Unstable Alcohol B 863F Ethoxylated 2.036.08 Unstable Alcohol B 863G Ethoxylated 8.10 0.00 Unstable Alcohol C863H Ethoxylated 4.05 4.05 Unstable Alcohol C 863I Ethoxylated 2.03 6.08Unstable Alcohol C 863J Ethoxylated 8.10 0.00 Unstable Alcohol D 863KEthoxylated 4.05 4.05 Stable Alcohol D 863L Ethoxylated 2.03 6.08 StableAlcohol D 863M Ethoxylated 8.10 0.00 Unstable Alcohol E 863N Ethoxylated4.05 4.05 Stable Alcohol E 863O Ethoxylated 2.03 6.08 Stable Alcohol E

When introducing elements of the present invention or the preferredembodiment(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above compositions and processeswithout departing from the scope of the invention, it is intended thatall matter contained in the above description and shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

What is claimed is:
 1. An aqueous herbicidal concentrate solution comprising: (a) a glyphosate component comprising a salt of glyphosate in a concentration greater than 300 grams acid equivalent per liter; (b) an amidoalkylamine surfactant of structure (I):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from 1 to about 22 carbon atoms, R₂ and R₃, are each independently hydrocarbyl or substituted hydrocarbyl having from 1 to about 6 carbon atoms, and R₄ is hydrocarbylene having from 1 to about 6 carbon atoms; and (c) at least one co-surfactant comprising an alkoxylated tertiary amine, an alkoxylated quaternary amine, an alkoxylated tertiary etheramine, an alkoxylated quaternary etheramine, an alkoxylated etheramine oxide, an alkoxylated alcohol, a phosphate ester of alkoxylated tertiary amine, a phosphate ester of alkoxylated etheramine, a phosphate ester of alkoxylated alcohol, or a combination thereof; wherein the alkoxylated tertiary amine surfactant is of structure (II):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4 to about 22 carbon atoms, R₂ and R₃ are each independently hydrocarbylene having 2, 3, or 4 carbon atoms, and the sum of x and y is an average value ranging from about 2 to about 50; wherein the alkoxylated quaternary amine surfactant is of structure (III):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from 4 to about 22 carbon atoms, R₂ and R₃ are each independently hydrocarbylene having 2, 3, or 4 carbon atoms, R₄ is hydrocarbyl or substituted hydrocarbyl having from 1 to about 4 carbon atoms, the sum of x and y is an average value ranging from about 2 to about 50, and X is a charge balancing counter-anion; wherein the alkoxylated tertiary etheramine surfactant is of structure (IV):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4 to about 22 carbon atoms; R₂, R₃ and R₄ are each independently hydrocarbylene having 2, 3, or 4 carbon atoms; m is an average number from about 1 to about 10; and the sum of x and y is an average value ranging from about 2 to about 60; wherein the alkoxylated quaternary etheramine surfactant is of structure (V):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4 to about 22 carbon atoms; R₂, R₃ and R₄ are each independently a hydrocarbylene having 2, 3, or 4 carbon atoms; m is an average number from about 1 to about 10; the sum of x and y is an average value ranging from about 2 to about 60; R₅ is hydrocarbyl or substituted hydrocarbyl having from 1 to about 4 carbon atoms; and A is a charge balancing counter-anion; wherein the alkoxylated etheramine oxide surfactant is of structure (VI):

wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4 to about 22 carbon atoms; R₂, R₃ and R₄ are each independently hydrocarbylene having 2, 3, or 4 carbon atoms; m is an average number from about 1 to about 10; and the sum of x and y is an average value ranging from about 2 to about 60; wherein the alkoxylated alcohol surfactant is of structure (VIII): R₁—O—(R₂O)_(n)H  Structure (VIII) wherein R₁ is hydrocarbyl or substituted hydrocarbyl having from about 4 to about 22 carbon atoms; R₂ is hydrocarbylene having 2, 3, or 4 carbon atoms; n is an average value ranging from about 2 to about 50; wherein the phosphate ester of the alkoxylated tertiary amine surfactant is of structure (IXa) or structure (IXb):

wherein each R₁ is independently hydrocarbyl or substituted hydrocarbyl having from about 4 to about 22 carbon atoms, R₂ and R₃ are each independently hydrocarbylene having 2, 3, or 4 carbon atoms, the sum of each x and y group is independently an average value ranging from about 2 to about 60, and R₄ and R₅ are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl having from 1 to about 6 carbon atoms; wherein the phosphate ester of alkoxylated etheramine surfactant is of structure (Xa) or structure (Xb):

wherein each R₁ is independently hydrocarbyl or substituted hydrocarbyl having from about 4 to about 22 carbon atoms; each R₂, R₃ and R₄ are each independently hydrocarbylene having 2, 3, or 4 carbon atoms; each m is independently an average number from about 1 to about 10; the sum of each x and y group is independently an average value ranging from about 2 to about 60; and R₅ and R₆ are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl having from 1 to about 6 carbon atoms; and wherein the phosphate ester of alkoxylated alcohol surfactant is of structure (XIa) or (XIb):

wherein each R₁ is independently hydrocarbyl or substituted hydrocarbyl having from about 4 to about 22 carbon atoms; each R₂ is independently hydrocarbylene having 2, 3, or 4 carbon atoms; each m is independently an average number from about 1 to about 60; and R₃ and R₄ are each independently hydrogen, hydrocarbyl or substituted hydrocarbyl having from 1 to about 6 carbon atoms.
 2. The solution of claim 1 wherein, in structure (I), R₁ is alkyl having an average of from about 4 carbon atoms to about 18 carbon atoms, and R₂ and R₃ are each alkyl having from 1 to 4 carbon atoms, and R4 is alkylene having from 1 to 4 carbon atoms.
 3. The solution of claim 1 wherein, in structure (I), R₁ is alkyl having an average of from about 5 carbon atoms to about 12 carbon atoms, R₂ and R₃ are methyl and R₄ is n-propylene.
 4. The solution of claim 1 wherein the co-surfactant comprises the alkoxylated tertiary amine of structure (II), wherein, in structure (II), R₁ is alkyl having from about 8 to about 18 carbon atoms, R₂ and R₃ are each independently ethylene, propylene or isopropylene, and the sum of x and y is an average value ranging from about 2 to about
 22. 5. The solution of claim 1 wherein the co-surfactant comprises the alkoxylated quaternary amine of structure (III), wherein, in structure (III), R₁ is alkyl having from about 8 to about 18 carbon atoms, R₂ and R₃ are each independently ethylene, propylene or isopropylene, R₄ is hydrocarbyl or substituted hydrocarbyl having from 1 to about 4 carbon atoms, and the sum of x and y is an average value ranging from about 2 to about
 22. 6. The solution of claim 1 wherein the co-surfactant comprises the alkoxylated tertiary etheramine of structure (IV), wherein, in structure (IV), R₁ is alkyl having from about 8 to about 18 carbon atoms; R₂, R₃, and R₄ are each independently ethylene, propylene or isopropylene; m is from about 1 to about 5; and the sum of x and y is an average value ranging from about 2 to about
 22. 7. The solution of claim 1 wherein the co-surfactant comprises the alkoxylated quaternary etheramine of structure (V), wherein, in structure (V), R₁ is alkyl having from about 8 to about 18 carbon atoms; R₂, R₃, and R₄ are each independently ethylene, propylene or isopropylene; R₅ is hydrocarbyl or substituted hydrocarbyl having from 1 to about 4 carbon atoms; m is from about 1 to about 5; and the sum of x and y is an average value ranging from about 2 to about
 22. 8. The solution of claim 1 wherein the co-surfactant comprises the alkoxylated etheramine oxide of structure (VI), wherein, in structure (VI), R₁ is alkyl having from about 8 to about 18 carbon atoms; R₂, R₃, and R₄ are each independently ethylene, propylene or isopropylene; m is from about 1 to about 5; and the sum of x and y is an average value ranging from about 2 to about
 22. 9. The solution of claim 1 wherein the co-surfactant comprises the alkoxylated alcohol of structure (VIII), wherein, in structure (VIII), R₁ is alkyl having from about 8 to about 18 carbon atoms; R₂ is ethylene, propylene or isopropylene; and n is an average value ranging from about 2 to about
 30. 10. The solution of claim 1 wherein the co-surfactant comprises the phosphate ester of alkoxylated tertiary amine of structure (IXa) or (IXb), wherein, in structures (Ixa) and (Ixb), each R₁ is alkyl having from about 8 to about 18 carbon atoms; R₂ and R₃ are each independently ethylene, propylene or isopropylene; the sum of each x and y group is an average value ranging from about 2 to about 22; and each R₄ and R₅ are hydrogen, hydrocarbyl or substituted hydrocarbyl having from 1 to about 6 carbon atoms.
 11. The solution of claim 1 wherein the co-surfactant comprises the phosphate ester of alkoxylated etheramine surfactant of structure (Xa) or (Xb), wherein, in structures (Xa) and (Xb), each R₁ is independently an alkyl having from about 8 to about 18 carbon atoms; each R₂, R₃ and R₄ are each independently ethylene, propylene or isopropylene; each m is independently an average number from about 1 to about 5; the sum of each x and y group is independently an average value ranging from about 2 to about 22; and R₅ and R₆ are hydrogen, hydrocarbyl or substituted hydrocarbyl having from 1 to about 6 carbon atoms.
 12. The solution of claim 1 wherein the co-surfactant comprises the phosphate ester of alkoxylated alcohol surfactant of structure (XIa) or (XIb), wherein, in structures (XIa) or (XIb), each R₁ is independently an alkyl or an alkylphenyl having from about 8 to about 18 carbon atoms; each R₂ is independently ethylene, propylene or isopropylene; each m is independently an average number from about 9 to about 15; and R₃ and R₄ are hydrogen, hydrocarbyl or substituted hydrocarbyl having from 1 to about 6 carbon atoms.
 13. The solution of claim 1 wherein the glyphosate salt is selected from the group consisting of potassium salt, monoammonium salt, diammonium salt, triammonium salt, sodium salt, monoethanolamine salt, isopropylamine salt, n-propylamine salt, ethylamine salt, dimethylamine salt, ethylenediamine salt, hexamethylenediamine salt, monosulfonium, disulfonium, trimethylsulfonium salt, and combinations thereof.
 14. The solution of claim 13 wherein the glyphosate salt is selected from the group consisting of the diammonium salt, the potassium salt, the monoethanolamine salt, and combinations thereof.
 15. The solution of claim 1 wherein the glyphosate component concentration is at least 90% by weight potassium salt of glyphosate.
 16. The solution of claim 1 wherein the weight ratio of glyphosate in grams acid equivalent to total surfactant in grams is from about 2:1 to about 10:1.
 17. The solution of claim 1 wherein the glyphosate concentration is greater than 360 grams acid equivalent per liter.
 18. The solution of claim 1 wherein the glyphosate concentration is greater than 480 grams acid equivalent per liter.
 19. The solution of claim 1 wherein the mass concentration ratio of the amidoalkylamine surfactant of structure (I) to total co-surfactant is from about 5:1 to about 1:5.
 20. The solution of claim 3 wherein the mass concentration ratio of the amidoalkylamine surfactant of structure (I) to total co-surfactant is less than about 45:55.
 21. The solution of claim 3 wherein the mass concentration ratio of the amidoalkylamine surfactant of structure (I) to total co-surfactant is less than about 35:65.
 22. The solution of claim 1 further comprising a co-herbicide.
 23. A herbicidal method for killing or controlling unwanted plants, the method comprising applying to the foliage of the unwanted plants an application mixture formed by diluting the aqueous herbicidal concentrate solution of claim 1 with water. 